Material Guide
Material Guide
At Pro-Bolt, we work with premium-grade Titanium, Aluminium, and Stainless Steel to deliver high-performance fasteners trusted by professionals across Motorsport, Aerospace, and beyond. This guide offers an overview of the key specifications, properties, and advantages of each material we use - so you can make informed decisions based on strength, weight, corrosion resistance, and application. Whether you're building for speed, durability, or style, understanding the materials is the first step in choosing the right fastener for the job.
We manufacture 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.
Aluminium
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.
| Typical Mechanical Properties of Aluminium | |
|---|---|
| Density | 2730 kg/m³ (170 lb/ft³) |
| Young's Modulus | 72 GPa (10.4 x 10⁶ psi) |
| Yield Strength | 505 MPa (120 x 10³ psi) |
| Ultimate Tensile Strength | 570 MPa (73.2 x 10³ psi) |
| Compressive Strength | 505 MPa (82.7 x 10³ psi) |
| 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.
| Typical Mechanical Properties of Stainless Steel | |
|---|---|
| Density | 8030 kg/m³ (501 lb/ft³) |
| Young's Modulus | 193 GPa (28 x 10⁶ psi) |
| Yield Strength | 260 MPa (37.7 x 10³ psi) |
| Ultimate Tensile Strength | 570 MPa (82.7 x 10³ psi) |
| Compressive Strength | 260 MPa (37.7 x 10³ psi) |
| Shear Modulus | 78 GPa (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 | 32.4 kNm/kg |
| Stiffness-to-Weight Ratio | 24 MNm/kg |
Titanium
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 nano-composite coating.
| Typical Mechanical Properties of Titanium | |
|---|---|
| Density | 4420 kg/m³ (276 lb/ft³) |
| Young's Modulus | 110 GPa (16 x 10⁶ psi) |
| Yield Strength | 828 MPa (120 x 10³ psi) |
| Ultimate Tensile Strength | 1030 MPa (149 x 10³ psi) |
| Compressive Strength | 960 MPa (139 x 10³ psi) |
| Shear Modulus | 43 GPa (6.24 x 10⁶ psi) |
| Ductility | 10% elongation at break |
| Poisson's Ratio | 0.34 |
| Hardness | 36 Rockwell C |
| Strength-to-Weight Ratio | 187 kNm/kg |
| Stiffness-to-Weight Ratio | 24.9 MNm/kg |