AISI 4130 Alloy Steel

AISI 4130 steel stockholders and suppliers. AISI 4130 is a chromium molybdenum alloy steel available as full bar lengths or cut pieces with delivery to the whole of the UK. It is  commonly supplied as round bar in the hardened and tempered condition with a hardness of 18-22 HRc. With a lower carbon content range AISI 4130 provides better weldability, at the expense of through thickness strength, than that of other oil and gas steel grades such as AISI 4140. AISI 4130 alloy steel is readily machineable in the supply condition of 18-22 HRc.

We welcome export enquiries for AISI 4130 steel. Contact our sales office and consult our shipping policy for further details.

Alternative oil and gas steel grades we supply

4140 | 4145 | 4330V | 4340 | 8620 | 6150

Form of Supply

West Yorkshire Steel are AISI 4130 steel stockholders and suppliers of round bar. Diameters can be supplied as full bar lengths or cut blanks. AISI 4130 ground steel bar can be supplied, providing a high tensile alloy steel precision ground bar to tight tolerances.

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  • Diameter

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AISI 4130 is widely used for a variety of applications in the oil and gas sector. Typical applications include components such as valve bodies, pumps and fittings.

Carbon 0.28-0.33% Chromium 0.90-1.10%
Manganese 0.40-0.60% Molybdenum 0.15-0.25%
Silicon 0.10-0.35% Phosphorous 0.035% max
Nickel 0.25% max Sulphur 0.040% max

Preheat carefully, then raise temperature to 950-1200°C for forging. Do not forge below 950°C.

Heat the AISI 4130 slowly to 850°C and allow enough time for the steel to be thoroughly heated. Cool slowly in the furnace to 480°C followed by air cooling.

When parts are heavily machined, ground or otherwise subject to cold work, stress relieving will be beneficial prior to any hardening.

AISI 4130 steel is usually supplied ready heat treated with a hardness of 18-22HRC. If further heat treatment is required annealed AISI 4130 should be heated slowly to 870-890°C and after adequate soaking at this temperature quench in oil. Temper as soon as tools reach room temperature.

Heat carefully to a suitable temperature selected by reference to a tempering chart or table (usually between 400-570°C, soak at the temperature for 2 hours per 25mm of ruling section, then all to cool in the air. Tempering between 250-375°C is not advised as tempering within this range will seriously reduce the impact value.

Proof Stress
of Area %
Min 95 75 20 40 18 217
Max 130 110 22 235

(*at room temperature heat treated to 18-22HRc)

Heat treatment temperatures, including rate of heating, cooling and soaking times will vary due to factors such as the shape and size of each component. Other considerations during the heat treatment process include the type of furnace, quenching medium and work piece transfer facilities. Please consult your heat treatment provider for full guidance on heat treatment of AISI 4130 alloy steel.

AISI 4130 alloy steel is available with a cast and analysis certificate or a BS EN 10204 3.1 mill certificate, please request when placing any orders.

AISI 4130 round bar is supplied in accordance with our ISO 9001:2015 registration.