Bumax High-Tensile Stainless Fastener Range — Quick Reference (Swedish)
Bumax is the Swedish precision fastener manufacturer — high-tensile stainless steel fasteners in Grade 8.8 + 10.9 + 12.5 strength classifications. Proprietary alloy delivers carbon-steel-equivalent strength in stainless body. Solves the "need corrosion-resistant AND high-strength" engineering problem.
| Bumax Grade | Tensile Strength | Equivalent Carbon Steel Grade |
|---|---|---|
| Bumax 88 | 800 MPa | Grade 8.8 — medium-high tensile |
| Bumax 109 | 1,040 MPa | Grade 10.9 — high tensile |
| Bumax 125 | 1,250 MPa | EXCEEDS Grade 12.9 — highest SS tensile available |
| Hex Bolts + Socket Head Cap Screws | Workshop range — see SHCS | — |
| Stainless 316 Material | Marine + chemical chloride resistance | — |
| 304 Bumax (Lower Cost) | General corrosion + indoor outdoor | — |
| Standard ISO + DIN Dimensions | Drop-in replacement for ISO/DIN spec fasteners | — |
Why Bumax matters: Standard stainless fasteners (304/316) max out at ~500-700 MPa tensile strength — half of high-tensile carbon steel. For engineering applications needing BOTH chloride/chemical corrosion resistance AND high tensile strength (marine engineering + pharma + chemical + aerospace + critical engineering), Bumax is the standard solution. Price: 5-10× standard stainless — but mandatory where engineering load case demands strength + corrosion combined. Brand: Bumax. Companion: stainless fasteners, SHCS, hex bolts + nuts, all fasteners.
Bumax High Tensile Stainless Steel Bolts, Nuts, Washers & Fasteners
Bumax is a Swedish precision fastener manufacturer producing high-tensile stainless steel fasteners in Grade 8.8 and Grade 10.9 strength classifications — the product of a proprietary alloy engineering and cold-working process that delivers tensile ratings previously achievable only in carbon and alloy steel fasteners, in a fully austenitic 316L stainless steel matrix. S
tandard stainless fasteners are available only to property class A2-70 or A4-70, providing 700 MPa tensile strength in metric grades. This is sufficient for many applications but falls well short of the 800 MPa (8.8) and 1040 MPa (10.9) ratings demanded by structural bolting, pressure vessel connections, offshore platform assemblies, and high-load process plant joints where corrosion resistance and full structural load rating must be achieved simultaneously from a single fastener.
The conventional engineering solution — galvanised or hot-dip carbon steel fasteners with periodic replacement as corrosion degrades them — is both operationally disruptive and progressively more expensive in environments with high corrosion rates.
Bumax eliminates this trade-off by engineering proprietary 316L formulations and processing routes that achieve 8.8 and 10.9 proof load and tensile strength in the corrosion-resistant stainless matrix.
The result is a fastener that performs as a structural bolt in terms of load rating and as a stainless fitting in terms of corrosion resistance — without the galvanic incompatibility issues that arise when mixing zinc-coated structural bolts with stainless structural elements.
Bumax is the standard specification for marine structures, desalination plants, chemical processing equipment, coastal infrastructure, offshore platforms, food and beverage processing machinery, and any bolted assembly where corrosion-driven fastener replacement would require disassembly of the joined structure. AIMS Industrial supplies Bumax hex bolts, hex nuts, socket head cap screws, set screws, lock nuts, flange nuts, and washers across Grade 8.8 and Grade 10.9 in 316L stainless. Order your Bumax fasteners today.
Shop Bumax high tensile stainless fasteners at AIMS Industrial alongside our Fasteners, Bremick, and Stainless Steel Fixings collections.
Order online, Contact our team for assistance or to Request a quote.
People Also Ask — Bumax High-Tensile Stainless Fasteners
Q: What is Bumax?
Bumax is a Swedish manufacturer of high-tensile stainless steel fasteners (since 1980) — premium stainless bolts with tensile strength approaching grade 12.9 carbon steel. The Bumax range (Bumax 88, 109, 125) offers stainless corrosion resistance combined with high mechanical strength — used where standard A2-70 or A4-70 stainless isn't strong enough but full carbon-steel grade 10.9/12.9 isn't corrosion-resistant enough. Specialty applications: marine engineering, offshore, mining headworks, structural stainless.
Q: Bumax 88, 109, 125 — what's the difference?
Bumax 88: 800 MPa tensile strength, equivalent to grade 8.8 carbon steel performance in stainless construction. Bumax 109: 1000 MPa tensile, equivalent to grade 10.9 in stainless. Bumax 125: 1250 MPa tensile, exceeds grade 12.9 strength in stainless construction. The number indicates the tensile strength × 10 MPa, similar to carbon steel grade nomenclature. Higher grade costs significantly more — use the lowest grade that meets the load requirement.
Q: When do I need Bumax over standard stainless?
Marine engineering structural connections: combined high load + saltwater exposure. Mining heap-leach and headworks: combined chemical + structural loading. Offshore platforms: critical structural members with corrosion exposure. Hydrogen-fuel infrastructure: high-pressure piping with stainless corrosion requirements. For these applications, Bumax delivers the combination of strength and corrosion resistance that no other fastener type matches. For general workshop and standard construction, standard A2/A4 stainless is sufficient.
Q: Bumax vs A4-80 stainless?
A4-80: 800 MPa tensile, premium stainless grade widely available. Cost-effective, similar strength to Bumax 88. Bumax 88: similar performance, slightly higher cost, Swedish manufacturing. Bumax 109 and 125: significantly higher strength than A4-80 — no equivalent in standard ISO 3506 stainless grades. For applications requiring above 800 MPa stainless, Bumax is the only option. For 800 MPa requirements, A4-80 may be more cost-effective.
Q: Where can I get Bumax fasteners?
Browse [/collections/bumax](/collections/bumax) for AIMS's Bumax range. Many Bumax sizes are special-order from Sweden with 4-8 week lead times — for specific size and grade requirements, contact AIMS with the bolt spec, grade, length, and quantity. For workshop applications, standard A2-70 or A4-70 stainless typically meets requirements at much lower cost — use Bumax only where the combined strength + corrosion is genuinely required.