Specialty Bolts

Stud Bolts

January 12, 2017 By Sigma Fasteners

Stud Bolts

Stud bolts are available in ASTM Grades B7, L7, B16, B16M, L7M, B8, 660 and B8M; they are also available exotic metals such as Monel, Titanium, Inconel, Alloy 20, and Hastelloy, 17-4PH. These studs are also available with industrial coatings such as SermaGard, Xylan, PTFE, Fluoropolymers and other coatings.

Stud Bolts for Pressure-Temperature Piping

Continuous Thread Studs (Fully Threaded Studs)

Stud bolts are threaded end to end and are often used for flange bolting with two nuts on either end.

There are two types of these studs.

Type one – usually for general purpose; the length of stud is measured from end to end. Threads are UNRC-2A.
Type two – studs for high temperature pressure piping. These studs are made to dimensional standard requirements of ANSI B16.5 the length of this stud is measured from first thread to first thread, exclusive of points. Threads are UNRC-2A for sizes 1 inch and under and 8 UNR-2A for sizes over 1 inch. The length of stud bolt, measured parallel to the axis, is the distance from first thread to first thread. First thread is defined as the intersection of the major diameter of the thread with the base of the point.

Double End Stud Bolts

Tap End Stud Bolts

ASTM Material Selection Chart

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