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Use the 5/16-18 x 4 18-8 stainless hex head cap screw when the assembly calls for side wrench access and a general-purpose bolt pattern. In this size range it is treated as a hex head cap screw, with the hex head driven by external tooling rather than an internal socket.

Common application reviews include HVAC equipment, conveyor structures, and retrofit repairs. 18-8 stainless is not a graded or heat-treated fastener; where certified high clamp loads govern, a graded steel hex bolt is the better tool.

18-8 stainless steel is an 18% chromium and 8% nickel austenitic stainless material used for ordinary atmosphere, moisture exposure, washdown, and clean appearance. Cold Headers serves maintenance and production needs where exact-size stainless hardware matters more than generic substitution.

Technical Highlights

  • Material: 18-8 Stainless Steel
  • Thread Size: 5/16-18
  • Length: 4 in.
  • Head Style: Hex
  • Drive: External Hex (wrench or socket driven)
  • Width Across Flats: 0.181-0.188 in.
  • Wrench Size: 3/16 in.
  • Head Height: 0.049-0.060 in.
  • Dimensional Standard: ASME B18.2.1
  • Material Standard: ASTM F593

Call 773-775-7900 or email Sales@coldheaders.com for pricing, availability, or a quote.

Unit of Measure

Specifications

Brands

 N/A Cold Headers, Inc.

Diameter

 N/A 5/16-18

Length

 N/A 4 in

Maximum Width Across the Flats

 N/A 0.188 in

Minimum Width Across the Flats

 N/A 0.181 in

Minimum Width Across Corners

 N/A 0.202 in

Maximum Head Height

 N/A 0.060 in

Minimum Head Height

 N/A 0.049 in

Material

 N/A 18-8 Stainless Steel

Quantity

 N/A 50

Package Type

 N/A Box

Search

 N/A SSHHCMS.5/16-18.4

Note

Note

 N/A Less Than Package Quantity Specified Plus 25%.