Double End Studs

January 11, 2017 by · Leave a Comment 


Double End Studs – Double ended studs

Double End Studs Bolts

Double End Studs

At Sigma Fasteners we provide mission critical bolting products for the nations leading manufacturers of pressure control equipment for controlling pressures during drilling and oil production.

Double-end studs used by many of these manufacturers have equal-length threads on each end to accommodate a nut and are threaded to a Class 2A fit. Length of stud is measured overall. Both ends have chamfered points, but round points may be furnished on either or both ends at the manufacturer’s option, This style is furnished in the same four types listed for tap-end studs. Double-end studs are used for flange bolting or other applications where torching from both ends is necessary or desirable.

Most steel grades not heat treated or quenched and tempered can be furnished on special order for production quantities. Only the Type 2 continuous thread studs made to specification ASTM A193 grade B7 are stocked in a full range of sizes.

ASTM Material Selection Chart B7, B7M, L7, L7M, 660, 718 Inconel, MP35N

B7M Bolts

February 19, 2016 by · Leave a Comment 

ASTM A193 Grade B7M Bolt

B7M Stud Bolts

B7M Studs

Bolt Description:

B7M bolts for High Temperature and/or High Pressure service are modified in our tempering furnace to meet the ASTM A193 /A193M  –  B7M standard for bolting covering both metric and inch bolting products. The A193 B7M standard covers threaded rod, bolts, studs, and stud bolts.  In accord with the A193 standard the final modification is the tempering at 1150° F minimum performed after all machining, roll threading and any type of cutting. The tempering furnace recording chart is kept on record with your order maintaining complete traceability of your final product. Tensile and 100% hardness records are also available and kept with your order.

Typical Usage:

Typical use for B7M bolting includes sour gas service where Hydrogen Sulfide gas exposure may lead to Hydrogen embrittlement problems in hard alloys.

Product marking:

All B7M bolting which has been 100% hardness tested must be marked B7M and will have the Sigma Trademarked S for manufacturer’s identification.


B7M bolts are 100% indentation hardness tested to ensure conformance to the standard. Tensile Tests are performed after tempering.


ASTM A194 2HM heavy hex nuts are most commonly used with ASTM A193 B7M bolts.

Catalog: Stud Bolts Heavy Hex Bolts