Fasteners

Sigma Fasteners manufactures and distributes a wide range of fasteners and bolting products – Fasteners for industry ranging from ½ through 4” and larger – In metric sizes M3 – M48 and larger. While Sigma is a full line distributor for all fastener products we specialize in custom bolts and custom bolting products for energy. Whether in emerging energy fields such as wind turbine bolting or legacy energy fields needing NACE certified MRO175 Sigma has the expertise to supply or custom manufacture all your bolting requirements. Our people have many years of experience in handling the most demanding expectations including the rigors North Slope of Alaska, to the regulatory hurdles of the South Texas Nuclear Project. Sigma Fasteners is ISO 9001:2001 certified and daily our associates deal with custom manufacturing many of the largest pressure and flow control equipment manufactures in the world. Sigma knows how to meet or exceed expectations of the most demanding fastener specifications in the industry. In addition, to distributing and manufacturing custom fasteners, Sigma also has fastener coating and fasteners plating capabilities that allow us control over your demanding needs.  Let Sigma be the answer to all your bolting needs.

The links below are from our standard fasteners catalog and includes items in stock and special order.

Nuts Bolts and Screws

Screws
Round Head Screws
Various Head Styles Machine Scerws
Tapping Screws (Approx. Hole Sizes)
Thumb and Wing Screws

B7 Studs and Nuts
Stud Bolts for Pressure-Temperature Piping
General Purpose End-to-End Studs
Tap End Stud Bolts
Double End Stud Bolts

Bolts
Hex Cap Screws (Finished Hex Bolts)
Wrench Openings for Square and Hex Bolts and Screws
Heavy Hex Bolts
Heavy Hex Structural Bolts
High-Strength Structural Bolting
Carriage Bolts and Lag Bolts
Square Bolts
Step Bolts and Countersunk Head Elevator Bolts

Nuts
Finished and Heavy Hex Nuts
Hexagon Machine Screw Nuts
Type A Forged Wing Nuts
Hex Slotted Nuts
Hex and Heavy Hex Jam Nuts
Hex Castle Nuts
Large Diameter Hexagon Head Cap Nuts
Round Spanner Nuts
Heavy Hex Nuts with Tommy Bar Holes

Sockets & Pins
Socket Head Cap Screws
Button Head and Flat Head Socket Cap Screws
Socket Set Screws
Hexagon Keys and Bits
Socket Head Shoulder Screws, Dowel Pins, and Slotted Set Screws
Square Head Set Screws and Socket Pipe Plugs
Physical Properties of Sockets
Point Terminology
Flange 12-Point Screws
Taper Pins
Threaded Taper Pins
Dowel Pins
Roll Pins
Cotter Pins

Washers
USS Wrought Washers
Stainless Steel Washers
S.A.E. Washers
Brass Washers
Beveled Washers
Spring Lock Washers
Tooth Lock Washers
Belleville Washers

Anchors
Wedge Anchors
Drop-In Anchors
Single Expansion Anchors
Machine Screw Anchors
Lag Shields
Lead Wood Screw Anchors
Hammer drive Anchors
Hollow Wall Anchors
Toggle Bolts
Toggle Wings and Nylon Nail Anchors
Plastic Anchors and Toggles

Locknuts
ESNA® Light Hex Nuts
FLEXLOC® Self-Locking Nuts
Prevailing-Torque Type Steel Hex and Hex Flange Nuts
ANCO Self-Locking Nuts

Self-Sealing Screws
Plated Carbon Steel
Stainless Steel
Plated Steel Self-Drilling

Self-Locking Fasteners

U-Bolts and Eye Bolts
Anchor Bolts & Bent Bolts
A-Bolts, Standard
U-Bolts, Long Tangent
Eyebolts-Regular Pattern
Eyebolts-Shoulder Pattern
Rod End Eyebolt Blanks

Metric Fasteners
Metric Hex, Head Cap Screws
Weights of Metric Hex Head Cap Screws
Metric Socket Cap Screws & Metric Flat Head Socket Caps
Metric Socket Set Screw & Metric Button Socket Caps
Metric Hex Nuts
Metric Flatwashers
Metric Internal & External Tooth Washers
Metric Lockwashers