Socket Head Cap Screws & Nuts, Steel


  • Imperial Sizes: 2-56, 4-40, 8-32, and 1/4"-20
  • Metric Sizes: M3 x 0.5, M4 x 0.7, and M6 x 1.0
  • Vented, Vacuum-Compatible Cap Screws Available
  • Nuts, Washers, and Counterbore Adapters Also Available

SH25S075

1/4"-20 Cap Screws,
3/4" Long

SH6MS16V

Vented, Vacuum-Compatible
M6 Cap Screws, 16 mm Long

SH3M8

M3 x 0.5 Cap Screws,
8 mm Long

W8S038

#8 Washers

SH8S15

8-32 Cap Screws
1.5" Long

N25S0440

1/4"-20 Nuts

Related Items


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Features

  • 2-56, 4-40, M3 x 0.5, 8-32, M4 x 0.7, 1/4"-20, and M6 x 1.0 Socket Head Cap Screws
  • Stainless or Alloy Steel Construction
  • Vented, Vacuum-Compatible 8-32, M4 x 0.7, 1/4"-20, and M6 x 1.0 Cap Screws Available
  • 8-32, M4 x 0.7, 1/4"-20, and M6 x 1.0 Nuts
  • #8 (M4) to 1/4" (M6) Counterbore Adapters Also Available
  • Ideal for Replenishing our Hardware Kits

Cap screws are an essential part of any lab setup. On this page, Thorlabs offers standard cap screws, nuts, and washers in many popular sizes, plus vented, vacuum-compatible 8-32, M4 x 0.7, 1/4"-20, and M6 x 1.0 cap screws. We also offer setscrews and thumbscrews, low-profile screws, screw kits, and balldrivers / hex keys.


Posted Comments:
Seoyoung Kwak  (posted 2023-11-21 15:56:26.523)
Hello, Can you please give me an answer that this screw can be used for optical table?
jdelia  (posted 2023-11-21 12:13:21.0)
Thank you for contacting Thorlabs. The screw you are referring to is SH6MS20, which is an M6 threaded cap screw. Since our metric tables contain M6 tapped holes, they can in fact be used with these screws.
li yancheng  (posted 2022-06-15 06:35:54.5)
Can SH2S019 fit in FCM13/M? In the top of FCM13/M,there is a screw hole,can SH2S019 fit in this hole? https://www.thorlabs.com/thorproduct.cfm?partnumber=FCM13/M#ad-image-0
jdelia  (posted 2022-06-15 01:51:46.0)
Thank you for contacting Thorlabs. If you are referring to the M4 tapped hole, then the SH2S019 cannot be used, but if you are referring to the hole featuring the securing cap screw, then yes this screw can be used as that hole is 2-56 threaded.
user  (posted 2022-02-04 12:34:16.433)
Hi, We can buy the same nuts from McMaster pack of 100 for $ 5.07. https://www.mcmaster.com/91841A009/ Why these are so expensive...
jdelia  (posted 2022-02-04 03:49:40.0)
Thank you for contacting Thorlabs. Our goal is to be a one-stop shop for photonics tools and accessories to optimize convenience for our customers. Although we might not make certain components in-house, we keep them in our inventory to offer them alongside other products with which they can be best utilized. However, we can only afford to sell these with a markup due to labor costs including shipping and handling. That being said, we can certainly look into making our prices more affordable.
Cheryl Vorvick  (posted 2021-04-22 14:30:59.057)
I need to know the dimensions of the head of the screw. Maybe I missed the note that says "here are the dimensions?" Having a drawing of every screw is probably a lot of work, but for me, without those dimensions I can't buy your screws, I have to keep looking.
YLohia  (posted 2021-04-22 03:12:16.0)
Hello, the head of the SH25S075V screw that you inquired about has a diameter of 0.375" +0.000"/-0.021" and a height of 0.247" +/-0.003.
david.vogt  (posted 2018-01-22 11:10:48.997)
Hello, I have a quick question concerning the 4-40 cap screws. I want to fix a thin plate to a cage system, and in order to do this, I am thinking of using these 4-40 cap screws. However, I could not find the depth of the 4-40 hole in the cage rods anywhere, so I don't know which length to use. Will the SH4S019 be fine, or will it be too short if my metal plate is about 1 mm thick? Will the SH4S025 be too long to properly tighten it? Thank you for your help.
tfrisch  (posted 2018-01-24 03:09:17.0)
Hello, thank you for contacting Thorlabs. The 4-40 screw we use in the extension rods is 1/4" long and protrudes about 0.1" (±10%), so the thread depth is about 0.15" ±0.01". If your plate is about 1mm thick (~0.04"), the longest screw you could use would be about 0.18" - 0.20" long. SH4S025 will be too long and SH4S019 will be really close with the tolerances. I will reach out to discuss your application directly as the thickness of your plate matters quite a bit here.
iain  (posted 2015-01-12 12:54:38.913)
What is the inner diameter and outer diameter of the 1/4"-20 (M6 compatible) washer W25S050?
cdaly  (posted 2015-01-12 04:59:08.0)
Response from Chris at Thorlabs: For the W25S050 washer, the inner and outer diameters are 0.265" and 0.500" respectively.
iain  (posted 2014-01-09 06:24:31.43)
Could you show the lengths of imperial screws in millimetres as well as inches. e.g. SH4S019 4-40, 3/16" (4.8 mm) long
sharrell  (posted 2014-01-17 08:41:31.0)
Response from Sean at Thorlabs: Thank you for your suggestion, we are adding the metric or imperial conversions of the screw lengths to the webpage now.
user  (posted 2013-09-20 16:05:58.097)
Could you sell M4x0.7x16mm cap screws (i.e. similar to say SH4MS12 but 16mm long).
jlow  (posted 2013-09-20 10:13:00.0)
Response from Jeremy at Thorlabs: We do not stock the 16mm long version of the M4 cap screws. We will look into the possibility of carrying this in the future.
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2-56 Stainless Steel Cap Screws

Item # Total Shank Length Hex Material Quantity
SH2S019 3/16" (4.8 mm) 3/32" 18-8 Stainless Steel 50
Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Imperial Price Available
SH2S019 Support Documentation
SH2S019Customer Inspired! 2-56 Stainless Steel Cap Screw, 3/16" Long, 50 Pack
$9.73
Today
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4-40 Stainless Steel Cap Screws

Item # Total Shank Length Hex Material Quantity
SH4S019 3/16" (4.8 mm) 3/32" 18-8 Stainless Steel 50
SH4S025 1/4" (6.4 mm)
SH4S031 5/16" (7.9 mm)
SH4S038 3/8" (9.5 mm)

We also offer the HW-KIT5 4-40 cap screw kit.

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Imperial Price Available
SH4S019 Support Documentation
SH4S019Customer Inspired! 4-40 Stainless Steel Cap Screw, 3/16" Long, 50 Pack
$8.79
Today
SH4S025 Support Documentation
SH4S025Customer Inspired! 4-40 Stainless Steel Cap Screw, 1/4" Long, 50 Pack
$8.58
Today
SH4S031 Support Documentation
SH4S031Customer Inspired! 4-40 Stainless Steel Cap Screw, 5/16" Long, 50 Pack
$8.85
Today
SH4S038 Support Documentation
SH4S038Customer Inspired! 4-40 Stainless Steel Cap Screw, 3/8" Long, 50 Pack
$9.50
Today
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M3 x 0.5 Stainless Steel and Alloy Steel Cap Screws

Item # Total Shank Length Hex Material Quantity
SH3M5 5 mm (0.20") 2.5 mm 18-8 Stainless Steel 50
SH3M06 6 mm (0.24") Grade 8 Alloy Steel
with Black Oxide Coating
SH3M8 8 mm (0.31")
SH3M10 10 mm (0.39")

We also offer the HW-KIT5/M M3 cap screw kit.

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Metric Price Available
SH3M5 Support Documentation
SH3M5Customer Inspired! M3 x 0.5 Stainless Steel Cap Screw, 5 mm Long, 50 Pack
$10.89
Today
SH3M06 Support Documentation
SH3M06Customer Inspired! M3 x 0.5 Alloy Steel Cap Screw, 6 mm Long, 50 Pack
$8.79
Today
SH3M8 Support Documentation
SH3M8Customer Inspired! M3 x 0.5 Alloy Steel Cap Screw, 8 mm Long, 50 Pack
$9.08
Today
SH3M10 Support Documentation
SH3M10Customer Inspired! M3 x 0.5 Alloy Steel Cap Screw, 10 mm Long, 50 Pack
$9.73
Today
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8-32 Stainless Steel Cap Screws

Please note that for 1.25" and 1.5" long screws, the threading does not extend the total length of the shank (see image to the bottom left); the threaded length and total shank length for each screw are provided in the table below.

Item # Total Shank Length Threaded Length Hex Material Quantity
SH8S025 1/4" (6.4 mm) 1/4" (6.4 mm) 9/64" 18-8 Stainless Steel 50
SH8S031 5/16" (7.9 mm) 5/16" (7.9 mm)
SH8S038 3/8" (9.5 mm) 3/8" (9.5 mm)
SH8S050 1/2" (12.7 mm) 1/2" (12.7 mm)
SH8S0625 5/8" (15.9 mm) 5/8" (15.9 mm)
SH8S075 3/4" (19.1 mm) 3/4" (19.1 mm)
SH8S100 1" (25.4 mm) 1" (25.4 mm)
SH8S1250 1.25" (31.8 mm) 0.95" (24.1 mm)
SH8S15 1.5" (38.1 mm) 1.15" (29.2 mm)

Cap Screw Dimensions
Item # Outer Diameter Inner Diameter Thickness Material Quantity
W8S038 0.375" +0.008"/-0.005" 0.172" +0.008"/-0.005" (#8 and M4 Compatible) 0.032" ± 0.008" 18-8 Stainless Steel 100

We also offer the HW-KIT1 8-32 cap screw kit.

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Imperial Price Available
SH8S025 Support Documentation
SH8S025Customer Inspired! 8-32 Stainless Steel Cap Screw, 1/4" Long, 50 Pack
$7.30
Today
SH8S031 Support Documentation
SH8S0318-32 Stainless Steel Cap Screws, 5/16" Long, 50 Pack
$7.47
Today
SH8S038 Support Documentation
SH8S038Customer Inspired! 8-32 Stainless Steel Cap Screw, 3/8" Long, 50 Pack
$7.43
Today
SH8S050 Support Documentation
SH8S050Customer Inspired! 8-32 Stainless Steel Cap Screw, 1/2" Long, 50 Pack
$7.89
Today
SH8S0625 Support Documentation
SH8S06258-32 Stainless Steel Cap Screws, 5/8" Long, 50 Pack
$8.13
Today
SH8S075 Support Documentation
SH8S075Customer Inspired! 8-32 Stainless Steel Cap Screw, 3/4" Long, 50 Pack
$8.50
Today
SH8S100 Support Documentation
SH8S100Customer Inspired! 8-32 Stainless Steel Cap Screw, 1" Long, 50 Pack
$9.08
Today
SH8S1250 Support Documentation
SH8S12508-32 Stainless Steel Cap Screws, 1.25" Long, 50 Pack
$9.33
Today
SH8S15 Support Documentation
SH8S158-32 Stainless Steel Cap Screws, 1.5" Long, 50 Pack
$14.55
Today
+1 Qty Docs Part Number - Universal Price Available
W8S038 Support Documentation
W8S038Customer Inspired! #8 Washer, M4 Compatible, Stainless Steel, 100 Pack
$3.94
Today
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Vented, Vacuum-Compatible 8-32 Cap Screws

Item # Total Shank Length Hex Material Quantity
SH8S038V 3/8" (9.5 mm) 9/64" 316 Stainless Steel 5
SH8S050V 1/2" (12.7 mm)
Vented Cap Screw
Click to Enlarge

These Cap Screws Have a Central Ø0.042" (Ø1.1 mm) Vent

These cap screws are constructed from 316 stainless steel and chemically cleaned and prepared for vacuum applications before packaging. They also have a central Ø0.042" (Ø1.1 mm) hole through the body of the screw to serve as a vent, allowing excess gas to escape from a blind hole when a vacuum chamber is pumped down.

They are compatible directly out of the packaging with vacuum environments down to 10-6 Torr. With additional cleaning and processing, they can be used at even lower pressures, only limited by the outgassing rate of the stainless steel. 316 Stainless Steel outgasses at a rate of 1.8 x 10-8 Torr-Liters/s/cm2. The material properties of the stainless steel and the cleaning methods that are completed by the end user should be used to determine the appropriateness of these products and materials in a specific vacuum system operating at pressures under 10-6 Torr.

These cap screws are packaged in double airtight bags for cleanroom and vacuum chamber applications. We also offer additional vacuum-compatible Ø1/2" post system components.

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Imperial Price Available
SH8S038V Support Documentation
SH8S038V8-32 Vacuum-Compatible Vented Cap Screw, 316 Stainless Steel, 3/8" Long, 5 Pack
$13.18
Today
SH8S050V Support Documentation
SH8S050V8-32 Vacuum-Compatible Vented Cap Screw, 316 Stainless Steel, 1/2" Long, 5 Pack
$13.72
Today
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M4 x 0.7 Stainless Steel Cap Screws

Please note that for 30 mm and 40 mm long screws, the threading does not extend the total length of the shank (see image to the bottom left); the threaded length and total shank length for each screw are provided in the table below.

Item # Total Shank Length Threaded Length Hex Material Quantity
SH4MS06 6 mm (0.24") 6 mm (0.24") 3 mm 18-8 Stainless Steel 50
SH4MS08 8 mm (0.31") 8 mm (0.31")
SH4MS10 10 mm (0.39") 10 mm (0.39")
SH4MS12 12 mm (0.47") 12 mm (0.47")
SH4MS16 16 mm (0.63") 16 mm (0.63")
SH4MS20 20 mm (0.79") 20 mm (0.79")
SH4MS25 25 mm (0.98") 25 mm (0.98")
SH4MS30 30 mm (1.18") 20.2 mm (0.80")
SH4MS40 40 mm (1.57") 20.2 mm (0.80")

Cap Screw Dimensions
Item # Outer Diameter Inner Diameter Thickness Material Quantity
W8S038 0.375" +0.008"/-0.005" 0.172" +0.008"/-0.005" (#8 and M4 Compatible) 0.032" ± 0.008" 18-8 Stainless Steel 100

We also offer the HW-KIT1/M M4 cap screw kit.

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
W8S038 Support Documentation
W8S038Customer Inspired! #8 Washer, M4 Compatible, Stainless Steel, 100 Pack
$3.94
Today
+1 Qty Docs Part Number - Metric Price Available
SH4MS06 Support Documentation
SH4MS06Customer Inspired! M4 x 0.7 Stainless Steel Cap Screw, 6 mm Long, 50 Pack
$7.54
Today
SH4MS08 Support Documentation
SH4MS08M4 x 0.7 Stainless Steel Cap Screw, 8 mm Long, 50 Pack
$8.36
Today
SH4MS10 Support Documentation
SH4MS10Customer Inspired! M4 x 0.7 Stainless Steel Cap Screw, 10 mm Long, 50 Pack
$7.84
Today
SH4MS12 Support Documentation
SH4MS12Customer Inspired! M4 x 0.7 Stainless Steel Cap Screw, 12 mm Long, 50 Pack
$8.15
Today
SH4MS16 Support Documentation
SH4MS16Customer Inspired! M4 x 0.7 Stainless Steel Cap Screw, 16 mm Long, 50 Pack
$8.20
Today
SH4MS20 Support Documentation
SH4MS20Customer Inspired! M4 x 0.7 Stainless Steel Cap Screw, 20 mm Long, 50 Pack
$8.79
Today
SH4MS25 Support Documentation
SH4MS25Customer Inspired! M4 x 0.7 Stainless Steel Cap Screw, 25 mm Long, 50 Pack
$9.08
Today
SH4MS30 Support Documentation
SH4MS30M4 x 0.7 Stainless Steel Cap Screw, 30 mm Long, 50 Pack
$9.33
Today
SH4MS40 Support Documentation
SH4MS40M4 x 0.7 Stainless Steel Cap Screw, 40 mm Long, 50 Pack
$9.88
Today
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Vented, Vacuum-Compatible M4 x 0.7 Cap Screws

Item # Total Shank Length Hex Material Quantity
SH4MS10V 10 mm (0.39") 3 mm A4 Stainless Steel 5
SH4MS12V 12 mm (0.47")
Vented Cap Screw
Click to Enlarge

These Cap Screws Have a Central Ø1.0 mm (Ø0.04") Vent

These cap screws are constructed from A4 stainless steel and chemically cleaned and prepared for vacuum applications before packaging. They also have a central Ø1.0 mm (Ø0.04") hole through the body of the screw to serve as a vent, allowing excess gas to escape from a blind hole when a vacuum chamber is pumped down.

They are compatible directly out of the packaging with vacuum environments down to 10-6 Torr. With additional cleaning and processing, they can be used at even lower pressures, only limited by the outgassing rate of the stainless steel. A4 Stainless Steel outgasses at a rate of 1.8 x 10-8 Torr-Liters/s/cm2. The material properties of the stainless steel and the cleaning methods that are completed by the end user should be used to determine the appropriateness of these products and materials in a specific vacuum system operating at pressures under 10-6 Torr.

These cap screws are packaged in double airtight bags for cleanroom and vacuum chamber applications. We also offer additional vacuum-compatible Ø1/2" post system components.

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Metric Price Available
SH4MS10V Support Documentation
SH4MS10VM4 x 0.7 Vacuum-Compatible Vented Cap Screw, A4 Stainless Steel, 10 mm Long, 5 Pack
$13.18
Today
SH4MS12V Support Documentation
SH4MS12VM4 x 0.7 Vacuum-Compatible Vented Cap Screw, A4 Stainless Steel, 12 mm Long, 5 Pack
$13.72
Today
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1/4"-20 Stainless Steel Cap Screws

Please note that for 1.5" and 2" long screws, the threading does not extend the total length of the shank (see image to the bottom left); the threaded length and total shank length for each screw are provided in the table below.

Item #a Total Shank Length Threaded Length Hex Material Quantity
SH25S025b 1/4" (6.4 mm) 1/4" (6.4 mm) 3/16" 18-8 Stainless Steel 25
SH25S038 3/8" (9.5 mm) 3/8" (9.5 mm)
SH25S050 1/2" (12.7 mm) 1/2" (12.7 mm)
SH25S063 5/8" (15.9 mm) 5/8" (15.9 mm)
SH25S075 3/4" (19.1 mm) 3/4" (19.1 mm)
SH25S100 1" (25.4 mm) 1" (25.4 mm)
SH25S1250 1.25" (31.8 mm) 1.25" (31.8 mm)
SH25S15 1.5" (38.1 mm) 1.07" (27.2 mm)
SH25S200 2" (50.8 mm) 1.12" (28.4 mm)
  • We also offer the HW-KIT2 1/4"-20 cap screw kit.
  • The price for these screws is higher due to the uncommon length.

Cap Screw Dimensions
Item # Outer Diameter Inner Diameter Thickness Material Quantity
W25S050 0.500" ± 0.010" 0.265" ± 0.010" (1/4" and M6 Compatible) 0.062" ± 0.010" 18-8 Stainless Steel 100
Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Imperial Price Available
SH25S025 Support Documentation
SH25S0251/4"-20 Stainless Steel Cap Screw, 1/4" Long, 25 Pack
$14.61
Today
SH25S038 Support Documentation
SH25S038Customer Inspired! 1/4"-20 Stainless Steel Cap Screw, 3/8" Long, 25 Pack
$9.08
Today
SH25S050 Support Documentation
SH25S0501/4"-20 Stainless Steel Cap Screw, 1/2" Long, 25 Pack
$9.45
Today
SH25S063 Support Documentation
SH25S063Customer Inspired! 1/4"-20 Stainless Steel Cap Screw, 5/8" Long, 25 Pack
$9.73
Today
SH25S075 Support Documentation
SH25S075Customer Inspired! 1/4"-20 Stainless Steel Cap Screw, 3/4" Long, 25 Pack
$10.33
Today
SH25S100 Support Documentation
SH25S100Customer Inspired! 1/4"-20 Stainless Steel Cap Screw, 1" Long, 25 Pack
$11.53
Today
SH25S1250 Support Documentation
SH25S12501/4"-20 Stainless Steel Cap Screw, 1.25" Long, 25 Pack
$13.84
Today
SH25S15 Support Documentation
SH25S151/4"-20 Stainless Steel Cap Screw, 1.5" Long, 25 Pack
$14.55
Today
SH25S200 Support Documentation
SH25S200Customer Inspired! 1/4"-20 Stainless Steel Cap Screw, 2" Long, 25 Pack
$15.08
Today
+1 Qty Docs Part Number - Universal Price Available
W25S050 Support Documentation
W25S050Customer Inspired! 1/4" Washer, M6 Compatible, Stainless Steel, 100 Pack
$5.44
Today
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Vented, Vacuum-Compatible 1/4"-20 Cap Screws

Item # Total Shank Length Hex Material Quantity
SH25S038V 3/8" (9.5 mm) 3/16" 316 Stainless Steel 5
SH25S050V 1/2" (12.7 mm)
SH25S063V 5/8" (15.9 mm)
SH25S075V 3/4" (19.1 mm)
SH25S100V 1" (25.4 mm)
Item # Outer Diameter Inner Diameter Thickness Material Quantity
W25S050V 0.505" ± 0.10" 0.286" ± 0.10" (1/4" and M6 Compatible) 0.064" ± 0.007" 316 Stainless Steel 25
Vented Cap Screw
Click to Enlarge

These Cap Screws Have a Central Ø0.0625" (Ø1.6 mm) Vent

These cap screws are constructed from 316 stainless steel and chemically cleaned and prepared for vacuum applications before packaging. They also have a central Ø0.0625" (Ø1.6 mm) hole through the body of the screw to serve as a vent, allowing excess gas to escape from a blind hole when a vacuum chamber is pumped down.

They are compatible directly out of the packaging with vacuum environments down to 10-6 Torr. With additional cleaning and processing, they can be used at even lower pressures, only limited by the outgassing rate of the stainless steel, which is 1.8 x 10-8 Torr-Liters/s/cm2. The material properties of the stainless steel and the cleaning methods that are completed by the end user should be used to determine the appropriateness of these products and materials in a specific vacuum system operating at pressures under 10-6 Torr.

These cap screws are packaged in double airtight bags for cleanroom and vacuum chamber applications. We also offer additional vacuum-compatible Ø1/2" post system components.

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Imperial Price Available
SH25S038V Support Documentation
SH25S038V1/4"-20 Vacuum-Compatible Vented Cap Screw, 316 Stainless Steel, 3/8" Long, 5 Pack
$11.64
Today
SH25S050V Support Documentation
SH25S050V1/4"-20 Vacuum-Compatible Vented Cap Screw, 316 Stainless Steel, 1/2" Long, 5 Pack
$20.34
Today
SH25S063V Support Documentation
SH25S063V1/4"-20 Vacuum-Compatible Vented Cap Screw, 316 Stainless Steel, 5/8" Long, 5 Pack
$14.15
Today
SH25S075V Support Documentation
SH25S075V1/4"-20 Vacuum-Compatible Vented Cap Screw, 316 Stainless Steel, 3/4" Long, 5 Pack
$16.55
Today
SH25S100V Support Documentation
SH25S100V1/4"-20 Vacuum-Compatible Vented Cap Screw, 316 Stainless Steel, 1" Long, 5 Pack
$23.87
Today
+1 Qty Docs Part Number - Universal Price Available
W25S050V Support Documentation
W25S050V1/4" (M6) Vacuum-Compatible Washer, 316 Stainless Steel, 25 Pack
$10.20
Today
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M6 x 1.0 Stainless Steel Cap Screws

Please note that for 35 mm and longer screws, the threading does not extend the total length of the shank (see image to the bottom left); the threaded length and total shank length for each screw are provided in the table below.

Item #a Total Shank Length Threaded Length Hex Material Quantity
SH6MS06b 6 mm (0.24") 6 mm (0.24") 5 mm 18-8 Stainless Steel 25
SH6MS10 10 mm (0.39") 10 mm (0.39")
SH6MS12 12 mm (0.47") 12 mm (0.47")
SH6MS16 16 mm (0.63") 16 mm (0.63")
SH6MS20 20 mm (0.79") 20 mm (0.79")
SH6MS25 25 mm (0.98") 25 mm (0.98")
SH6MS30 30 mm (1.18") 30 mm (1.18")
SH6MS35 35 mm (1.38") 25.2 mm (0.99")
SH6MS45 45 mm (1.77") 25.5 mm (1.00")
SH6MS50 50 mm (1.97") 25.5 mm (1.00")
  • We also offer the HW-KIT2/M M6 cap screw kit.
  • The price for these screws is higher due to the uncommon length.

Cap Screw Dimensions
Item # Outer Diameter Inner Diameter Thickness Material Quantity
W25S050 0.500" ± 0.010" 0.265" ± 0.010" (1/4" and M6 Compatible) 0.062" ± 0.010" 18-8 Stainless Steel 100
Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
W25S050 Support Documentation
W25S050Customer Inspired! 1/4" Washer, M6 Compatible, Stainless Steel, 100 Pack
$5.44
Today
+1 Qty Docs Part Number - Metric Price Available
SH6MS06 Support Documentation
SH6MS06M6 x 1.0 Stainless Steel Cap Screw, 6 mm Long, 25 Pack
$14.97
Today
SH6MS10 Support Documentation
SH6MS10Customer Inspired! M6 x 1.0 Stainless Steel Cap Screw, 10 mm Long, 25 Pack
$9.08
Today
SH6MS12 Support Documentation
SH6MS12Customer Inspired! M6 x 1.0 Stainless Steel Cap Screw, 12 mm Long, 25 Pack
$9.45
Today
SH6MS16 Support Documentation
SH6MS16Customer Inspired! M6 x 1.0 Stainless Steel Cap Screw, 16 mm Long, 25 Pack
$9.73
Today
SH6MS20 Support Documentation
SH6MS20Customer Inspired! M6 x 1.0 Stainless Steel Cap Screw, 20 mm Long, 25 Pack
$10.33
Today
SH6MS25 Support Documentation
SH6MS25Customer Inspired! M6 x 1.0 Stainless Steel Cap Screw, 25 mm Long, 25 Pack
$11.53
Today
SH6MS30 Support Documentation
SH6MS30M6 x 1.0 Stainless Steel Cap Screw, 30 mm Long, 25 Pack
$13.84
Today
SH6MS35 Support Documentation
SH6MS35M6 x 1.0 Stainless Steel Cap Screw, 35 mm Long, 25 Pack
$14.16
Today
SH6MS45 Support Documentation
SH6MS45M6 x 1.0 Stainless Steel Cap Screw, 45 mm Long, 25 Pack
$14.55
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SH6MS50 Support Documentation
SH6MS50Customer Inspired! M6 x 1.0 Stainless Steel Cap Screw, 50 mm Long, 25 Pack
$15.08
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Vented, Vacuum-Compatible M6 x 1.0 Cap Screws

Item # Total Shank Length Hex Material Quantity
SH6MS10V 10 mm (0.39") 5 mm A4 Stainless Steel 5
SH6MS12V 12 mm (0.47")
SH6MS16V 16 mm (0.63")
SH6MS20V 20 mm (0.79")
SH6MS25V 25 mm (0.98")
Item # Outer Diameter Inner Diameter Thickness Material Quantity
W25S050V 0.505" ± 0.100" 0.286" ± 0.100" (1/4" and M6 Compatible) 0.064" ± 0.007" 316 Stainless Steel 25
Vented Cap Screw
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These Cap Screws Have a Central Ø0.0625" (Ø1.6 mm) Vent

These cap screws are constructed from A4 stainless steel and chemically cleaned and prepared for vacuum applications before packaging. They also have a central Ø0.0625" (Ø1.6 mm) hole through the body of the screw to serve as a vent, allowing excess gas to escape from a blind hole when a vacuum chamber is pumped down.

They are compatible directly out of the packaging with vacuum environments down to 10-6 Torr. With additional cleaning and processing, they can be used at even lower pressures, only limited by the outgassing rate of the stainless steel, which is 1.8 x 10-8 Torr-Liters/s/cm2. The material properties of the stainless steel and the cleaning methods that are completed by the end user should be used to determine the appropriateness of these products and materials in a specific vacuum system operating at pressures under 10-6 Torr.

These cap screws are packaged in double airtight bags for cleanroom and vacuum chamber applications. We also offer additional vacuum-compatible Ø1/2" post system components.

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
W25S050V Support Documentation
W25S050V1/4" (M6) Vacuum-Compatible Washer, 316 Stainless Steel, 25 Pack
$10.20
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+1 Qty Docs Part Number - Metric Price Available
SH6MS10V Support Documentation
SH6MS10VM6 x 1.0 Vacuum-Compatible Vented Cap Screw, A4 Stainless Steel, 10 mm Long, 5 Pack
$8.75
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SH6MS12V Support Documentation
SH6MS12VM6 x 1.0 Vacuum-Compatible Vented Cap Screw, A4 Stainless Steel, 12 mm Long, 5 Pack
$14.29
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SH6MS16V Support Documentation
SH6MS16VM6 x 1.0 Vacuum-Compatible Vented Cap Screw, A4 Stainless Steel, 16 mm Long, 5 Pack
$15.36
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SH6MS20V Support Documentation
SH6MS20VM6 x 1.0 Vacuum-Compatible Vented Cap Screw, A4 Stainless Steel, 20 mm Long, 5 Pack
$19.44
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SH6MS25V Support Documentation
SH6MS25VM6 x 1.0 Vacuum-Compatible Vented Cap Screw, A4 Stainless Steel, 25 mm Long, 5 Pack
$27.59
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Stainless Steel Nuts

Item # Thread Thickness Hex Material Qty.
N8S0340 8-32 0.13" 11/32" 18-8 Stainless Steel 50
N25S0440 1/4"-20 0.22" 7/16"
N4MS07 M4 x 0.7 3.2 mm 7 mm
N6MS010 M6 x 1.0 5.0 mm 10 mm
  • Nuts for use with Cap Screws or Bolts
  • Available Threads: 8-32, 1/4"-20, M4 x 0.7, or M6 x 1.0
  • Sold in Packs of 50

We offer stainless steel nuts for retaining cap screws in unthreaded bores.

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Imperial Price Available
N8S0340 Support Documentation
N8S03408-32 Stainless Steel Nut, 50 Pack
$6.43
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N25S0440 Support Documentation
N25S04401/4"-20 Stainless Steel Nut, 50 Pack
$6.43
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+1 Qty Docs Part Number - Metric Price Available
N4MS07 Support Documentation
N4MS07M4 x 0.7 Stainless Steel Nut, 50 Pack
$6.43
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N6MS010 Support Documentation
N6MS010M6 x 1.0 Stainless Steel Nut, 50 Pack
$6.43
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Counterbore Adapter for Cap Screws

SD1 Adapter Ring in RC1 Rail Carrier
 Cross Section of RC2 Rail Carrier with Included SD1 Counterbore Adapter Ring
  • Use an 8-32 or M4 Cap Screw in a 1/4" or M6 Counterbore
  • Package of 10 Adapters

The SD1 stainless steel adapter ring allows an 8-32 or M4 cap screw to be used within the 1/4" or M6 counterbores found on many optomechanical components.

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
SD1 Support Documentation
SD11/4" (M6) to #8 (M4) Counterbore Adapter Ring, 10 Pack
$9.21
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