Material Guide

Pro-Bolt is proud to be Europe’s largest stockist of titanium and aluminum 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 using single process on multi-axis C.N.C. 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.



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.

  • 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 form-ability, strength, weld ability 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