BUMAX Grades

Different stainless steel grades are available to provide the optimal fastener solution to meet the needs of your specific application.

Essential properties, such as corrosion resistance, temperature resistance, mechanical strength and magnetic permeability, etc must be considered. Correctly chosen stainless steel grade will guarantee a trouble-free life span and low lifecycle cost. We are specialists and have a long experience of selecting the best material to optimally meet your particular needs.

BUMAX specializes in unique designs and custom-made fasteners developed together with our customers. However, we also keep a large stock of standardized products for immediate delivery.

Grade Strength, min
Fastener standard Micro structure C max Cr Ni Mo Other PRE¹
BUMAX 88 800/640 1.4432/36/35 A4 Austenitic 0.03 17 11.5 2.7 27
BUMAX 109 1000/900 1.4432/36/35 A4 Austenitic 0.03 17 11.5 2.7 27
BUMAX SA 800/640 1.4547, S31254 A8 Austenitic 0.02 20 18 6.2 N, Cu 43
BUMAX DX 129 1200/1080 1.4462, S32205 D6 Ferrite-Austenitic 0.03 22 5.2 3.2 N 36
BUMAX SDX 109 1000/900 1.4410, S32750 D8 Ferrite-Austenitic 0.03 25 7 4 N 42
BUMAX SDX NORSOK 750/550 1.4501/1.4410 S32760/S32750 Norsok M630 MDS D60 Ferrite-Austenitic 0.03 25 7 4 N, W, Cu 42
BUMAX ULTRA 1500/1350 Martensitic 0.02 12 9 4 Al, Ti, Cu 25
BUMAX HE 1000/900 1.4980, S66286 Austenitic 0.08 15 26 1.5 Ti, V
BUMAX HEP 1000/600 2.4952, N07080 Austenitic 0.10 19 >65 Al, Ti, Co


BUMAX 88® is a premium A4 fastener that offers better corrosion resistance than standard A4 due to higher molybdenum content.

BUMAX® 109

BUMAX® 109 is the strongest A4 fastener on the market. We use the same material as Bumax 88 but achieve higher strength due to a special manufacturing process.


BUMAX® SA is a 6Mo high-alloy austenitic stainless steel for seawater and other aggressive chloride bearing medias.


BUMAX® DX 129 is a duplex stainless steel product with very high strength combined with excellent corrosion resistance.


BUMAX® SDX 109 is a super duplex grade with excellent mechanical properties, and exceptional resistance to general crevice, pitting and stress corrosion in aggressive environments.


BUMAX® Ultra, a unique precipitation hardenable stainless steel that can be delivered in ultra-high strength levels.


BUMAX® HE is a high temperature resistant material for applications requiring high strength and good oxidation resistance at temperatures up to 700°C.


BUMAX® HEP is a high temperature resistant material with excellent oxidation resistance and high tensile and creep properties at temperatures up to 815°C.


BUMAX® SDX Norsok fasteners are accredited to NORSOK certification and can be provided in super duplex grades.

BUMAX is available worldwide

Our extensive network of sales offices and distributors makes it easy to get in touch with us. Find your local sales office or distributor below. For other countries not represented, please contact our Main Sales Office.

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