BS 970 Compliant Steel Forgings — British Standard Wrought Steel Grades (070M20, 817M40 & More) for UK & Commonwealth Engineering
Shivam Forge manufactures forged components to BS 970 (British Standard specification for wrought steels for mechanical and allied engineering purposes) grade designations — including 070M20, 080M40, 817M40, and their historic 'En' series equivalents — for UK, Commonwealth, and legacy North Sea oil and gas engineering customers standardizing to British material designations. Rajkot, India. Call +91-9265772827.
BS 970's designation system encodes genuinely useful metallurgical information directly into a compact six-character code, a structure that differs meaningfully from both the SAE/AISI four-digit system and the DIN/EN Werkstoffnummer convention: the first three digits identify the steel's composition series (for example, the 000–199 range covers carbon and carbon-manganese steels, while ranges above 500 cover alloy steels containing nickel, chromium, and molybdenum in various combinations), the middle letter indicates the condition the chemical composition and mechanical properties are specified to — 'M' for steels specified to mechanical property requirements (the most commonly ordered condition for forgings), 'A' for chemical composition to a specified analysis, 'H' for steels specified to hardenability requirements, and 'S' for silicon-killed (rimming-free) deoxidation practice — and the final two digits give the mean carbon content multiplied by 100. Understanding this code matters practically because BS 970 remains the specification base for a substantial installed base of UK and Commonwealth engineering drawings, including legacy North Sea oil and gas platform equipment specifications and general mechanical engineering documentation that predates and, in many companies, still coexists alongside EN and ISO harmonized standards. Many of these grades also carry historic 'En' series names — 070M20 corresponds closely to the older En3 designation, 817M40 to En24, 530M40 to En18 — names that remain in everyday use across UK engineering shop floors and purchasing departments even though the formal BS 970 six-character code is the current specification reference, meaning a forging supplier genuinely conversant in British steel specification needs fluency in both naming conventions to serve this market correctly.
Forged 070M20 blanks for general mechanical engineering components requiring a low-carbon, readily machinable and weldable steel, the British standard equivalent role to SAE 1020 in general fabrication use.
Forged 080M40 shaft and general engineering component blanks, a medium-carbon steel widely specified across UK general engineering for components requiring moderate strength through quench-and-temper heat treatment.
Forged 817M40 blanks — a nickel-chromium-molybdenum alloy steel — for high-strength shaft, gear, and structural components in UK heavy engineering, oil and gas, and defence-sector applications requiring properties comparable to AISI 4340.
Forged case-hardening steel blanks from the BS 970 800-series nickel-chromium alloy range for gear and shaft applications requiring a hard, wear-resistant carburized surface with a tough core, per UK engineering convention.
Chemical composition and mechanical property verification directly against the specified BS 970 grade code, including correct identification of the composition series, specified condition (M/A/H/S), and carbon content the designation encodes.
Material supplied and documented with cross-reference to the historic En series designation (En3, En8, En19, En24, En36, etc.) where a UK customer's drawing or purchasing system still references the older naming convention alongside or instead of the current BS 970 code.
Tensile, yield, elongation, and impact testing verifying compliance with the specified mechanical property condition for M-designated grades, the condition most commonly specified for forged mechanical components.
Material test certificates per EN 10204 3.1 as standard, with 3.2 third-party witnessed certification available, formatted to the documentation convention UK and Commonwealth engineering and oil and gas customers expect.
British Standard 970 occupies a specification niche that international buyers sometimes underestimate the persistence of: despite decades of European harmonization efforts that have brought EN steel designations into wide use across the UK alongside BS 970, a substantial base of British and Commonwealth engineering drawings, particularly in legacy oil and gas, defence, and heavy engineering sectors, continue to reference BS 970 grade codes directly, and in many cases the even older 'En' series names those codes historically replaced remain in everyday shop-floor and purchasing use. A forging supplier serving this market genuinely needs fluency in both naming conventions, not just the ability to look up a cross-reference table, because correctly interpreting a drawing that mixes formal BS 970 codes with informal En series references is a routine part of accurately quoting and manufacturing to UK specification.
The six-character BS 970 code itself rewards understanding rather than rote lookup: the three-digit composition series identifies the steel's fundamental alloy family, the letter indicates precisely what condition (chemical analysis, mechanical property, hardenability, or deoxidation practice) the material is actually specified and tested against, and the final two digits give mean carbon content directly. This structure means an engineer or buyer who understands the code can infer a great deal about a grade's likely properties and appropriate application even without looking it up — 817M40, for instance, immediately signals a nickel-chromium-molybdenum alloy steel specified to mechanical properties with roughly 0.40% carbon, characteristics that place it in the same functional territory as AISI 4340 for high-strength shaft and structural applications, even though the two specifications are not strictly interchangeable on exact chemistry tolerance.
For forging manufacturers outside the UK supplying into British and Commonwealth engineering supply chains, correctly manufacturing and certifying to BS 970 specification directly — rather than substituting a nominally 'equivalent' SAE or DIN grade and hoping it passes inspection — is what genuine drawing compliance requires, particularly for legacy North Sea oil and gas equipment and defence-sector components where specification traceability is scrutinized closely during supplier qualification and incoming inspection. Getting this right from the outset avoids the friction, and potential rejection risk, that specification mismatches introduce into UK customer quality acceptance processes.
For UK, Commonwealth, and legacy North Sea oil and gas engineering customers sourcing forged components to British Standard specification, Shivam Forge manufactures and certifies directly against BS 970 grade codes with historic En series cross-reference where helpful. Contact our engineering team at +91-9265772827 or sales@shivamforge.com with your drawing and grade requirement for a manufacturability review and quotation.
The '817' identifies the steel's composition series — a nickel-chromium-molybdenum alloy steel range — the 'M' indicates the material is specified to mechanical property requirements (the standard condition for forgings), and '40' indicates a mean carbon content of approximately 0.40%. This specific grade is closely equivalent to the historic En24 designation and broadly comparable to AISI 4340 in the SAE system.
BS 970 superseded the older En (Emergency Number) system that originated during WWII-era British steel standardization, and many current BS 970 grades map closely to specific En numbers — 070M20 to En3, 080M40 to En8, 817M40 to En24, for example. Both naming conventions remain in active everyday use across UK engineering, so we document and cross-reference both where helpful to a customer's purchasing and drawing system.
BS 970 uses a distinct six-character code encoding composition series, specified condition, and carbon content, differing structurally from both the SAE/AISI four-digit system and the DIN/EN Werkstoffnummer convention. Functionally comparable grades exist across all three systems (817M40 to AISI 4340, for instance), but exact chemistry tolerance bands and specified test requirements differ, so we manufacture and certify directly against whichever specification a customer's drawing actually calls out rather than treating the systems as interchangeable substitutes.
Yes. Case-hardening grades from the BS 970 800-series nickel-chromium alloy range are available for gear and shaft applications requiring carburized wear surfaces with a tough core, following UK engineering specification convention for case depth and core property verification.
Material test certificates per EN 10204 3.1 as standard, with 3.2 third-party witnessed certification available, referencing the correct BS 970 grade code and, where useful, the corresponding historic En series designation, in the documentation format UK and Commonwealth purchasing and quality systems typically expect.
Why Choose Shivam Forge
Shivam Forge delivers precision hot-forged components from our integrated Shapar, Rajkot facility — covering forging, CNC machining, heat treatment, and quality inspection under one roof.
