Material Guide

Pro-Bolt is proud to be Europe’s largest stockist of titanium and aluminium fasteners, along with a growing range of stainless steel products. Our uniquely designed bolts have been successfully tested in the field for the last four years, gaining us a reputation for high quality products, excellent customer service and prompt delivery. Since 1999, Pro-Bolt has supplied many of the top names in the world of Motorsport. We have now taken the initiative and are actively developing products suitable for the Marine Industry.

We manufacture in the UK using single process on multi-axis CNC machining centres, which includes thread rolling. Thread standards are to BS3692:1967, the British Standard for ISO Precision Metric Threads, and route radii vary between 0.8mm and 0.4mm, the maximum that we can use to improve shear strength. Thread lead varies between K1 and K2. We also supply items machined from bar.

We encourage trade enquiries and welcome the opportunity to provide you with a quotation


Made from aircraft grade titanium 6AL-4V (grade 5), the outstanding benefits are that we roll the threads to produce greater fatigue strength and reduce galling. These bolts are in excess of 120,000psi ultimate tensile strength, suitable to replace both Grade 5 and Grade 8 steel bolts. We offer Race Spec drilled Flanged Hex Head Bolts, Flanged Hex Head, Tapered Socket Cap, Countersunk Bolts, Dome Head Bolts, Nuts and Washers – from 3mm to 12mm.

Black Titanium: Long lasting finish resulting from an application of Diamond Like Coating (DLC). This unique finish increases the fastener lifetime and helps to prevent galling whilst providing a supreme hardness and offering the optimum in corrosion resistance thanks to a nanocomposite coating.

Density 4420kg/m3 (276lb/ft3)
Young's Modulus 110GPa (16 x 106psi)
Yield Strength 828 MPa (120 x 103 psi)
Ultimate Tensile Strength 1030MPa (149 x 103 psi)
Compressive Strength 960MPa (139 x 103 psi)
Shear Modulus 43GPa (6.24 x 106 psi)
Ductility 10% elongation at break
Poisson's Ratio 0.34
Hardness 36 Rockwell C
Strength-to-Weight Ratio 187kNm/kg
Stiffness-to-Weight Ratio 24.9MNm/kg


Manufactured from 7075T6 aluminium, and suitable for use in all non-safety critical areas, all products are available in a choice of black, blue, gold, orange, purple, red and silver. During manufacturing, the head is cold formed and the shank thread rolled. The anodising involves chemically brightening and colour anodising to between 8 and 12 microns thick. We offer Race Spec Drilled Flanged Hex Head, Socket Cap Bolts, Countersunk Bolts, Dome Head Bolts, Nuts and Washers – from 3mm to 10mm.

Density 2730kg/m3 (170lb/ft3)
Young's Modulus 72GPa (10.4 x 106 psi)
Yield Strength 505 MPa (120 x 103 psi)
Ultimate Tensile Strength 570 MPa (73.2 x 103psi)
Compressive Strength 505 MPa (82.7 x 103psi)
Shear Modulus 27 GPa (3.92 x 106 psi)
Shear Strength 330 MPa (47.9 x 103 psi)
Ductility 10% elongation at break
Poisson's Ratio 0.33
Hardness 150 Brinell
Strength-to-Weight Ratio 185 kNm/kg
Stiffness-to-Weight Ratio 26.4 Mnm/kg

Stainless Steel

Manufactured from A316 stainless steel. A316 stainless steel has a minimum chromium content of 16.5% and contains elements of carbon, molybdenum, silicon, phosphorus, sulphur, nickel, manganese and iron, all of which add properties of formability, strength, weldability and enhanced corrosion resistance. All of the fasteners are highly polished to a mirror-like finish.

Density 8030kg/m3(501lb/ft3)
Young's Modulus 193GPa (28 x 106psi)
Yield Strength 260MPa (37.7 x 103 psi)
Ultimate Tensile Strength 570MPa (82.7 x 103psi)
Compressive Strength 260MPa (37.7 x 103psi)
Shear Modulus 78GPa (11.3 x 106 psi)
Ductility 40% elongation at break
Poisson's Ratio 0.27
Hardness 95 Rockwell B+
Maximum value allowed by ASTM A240
Strength-to-Weight Ratio 32.4kNm/kg
Stiffness-to-Weight Ratio 24 MNm/kg