BUMAX®: the world’s strongest stainless steel fasteners
What is BUMAX?
BUMAX® is a premium range of high-tensile stainless steel fasteners. It matches the mechanical strength of carbon-steel property classes 8.8 and 10.9 while keeping the corrosion resistance of stainless steel.
At the top of the range, BUMAX ULTRA reaches Grade 17.9 — the strongest stainless bolts in the world — for the most demanding bolted joints.
Strength without the rust
Standard stainless (A2/A4) usually trades strength for corrosion resistance. BUMAX 88 and BUMAX 109 close that gap, delivering the same guaranteed tensile and yield strength as carbon-steel 8.8 and 10.9 — so you can design out the rust without dropping a strength class.
Corrosion resistance
Thanks to its chemical composition, BUMAX has a minimum PRE value over 25.7, rating it for around 10 years in a marine environment — well beyond regular A4/316 stainless.
Where BUMAX is used
- Subsea & marine — long-life joints in salt-water exposure.
- Renewables — offshore wind, tidal and solar structures.
- High-performance engineering — motorsport, aerospace-adjacent and precision machinery.
- Critical bolted joints — where failure isn’t an option.
Grades & certification
PTS stocks BUMAX in metric and inch, grades 88 and 109, and supplies it with full material certification, batch numbers and country of origin for complete traceability.
