Custom Bolts

Heavy Hex Bolts

January 21, 2017 By Sigma Fasteners

Heavy Hex Bolts

There are several ASTM bolting specifications that require a heavy hex head – larger than a standard or finished hex head. These specifications include: A193, A320 and A307B. Although A325 and A490 bolts also require a heavy hex head, they refer to Structural Bolts for dimensional specifications, since structural bolts have shorter thread lengths than standard heavy hex bolts.

Heavy Hex Bolts are used in a varity of OEM equipment and can be manufactured in multiple ASTM grades.

ASTM Material Selection Chart

Check Out Heavy Hex Bolts our Bolt Catalog for Sizes and Dimensions.

Double End Studs

January 11, 2017 By Sigma Fasteners

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

Custom Bolting to Print

April 19, 2016 By Sigma Fasteners

Sigma Fasteners specializes in manufacturing custom bolting products for Pressure Control, Petroleum Valve and oilfield equipment manufacturers.

Need a custom bolt manufactured for your company? Do you need a that non standard fasteners in a hurry? Simga Fasteners specilizes in custom bolting to meet your drawing, rev #, and specifications. We manufacture custom fasteners in all types of ASTM metals. If you need custom bolts, custom nuts or custom stud bolts, Sigma will deliver them on time. We do carry standard fasteners, but as custom fastener manufacturer, our reputation is built on meeting your demanding fastener needs.

Have a drawing send it on to us, our experienced sales people will take care of your custom fastener needs. We specialize in large diameter custom fastener for your products.

ASTM Material Selection Chart