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We are specialists in engineering materials support to improve the aerospace MRO supply chain.

Smiths MRO is a sub-divsion of a larger business - Smiths Advanced Metals.

Smiths MRO focuses on raw material support for the global aircraft maintenance, repair and overhaul market. Our business is supported by a broad and diverse stock range with a dedicated team that provides outstanding service levels required for our industry.

We often ship goods to our MRO customers on the same day.

4130 Sheet (AMS 6345)

Aerospace Steel Sheet

Our 4130 stainless steel sheets are classed as aircraft grade material.

4130 steel sheet is easy to weld and fabricate and benefits from mild hardenability.

4130 is known as 'an aerospace steel' and finds extensive use in aerospace engineering applications as one of the most popular steel sheet products in this market sector.

About 4130 Steel Sheet

The product is a through-hardened low alloy steel grade, offering excellent ductility, good workability and good wear/abrasion resistant characteristics. The alloy is often referred to as chrome moly (or chromoly) due to the material's chromium and molybdenum content. The impressive weldability of the alloy is at the expense of through thickness strength. The product combines reasonable strength, toughness and fatigue strength. Good atmospheric corrosion resistance is also a feature.


4130 steel sheet is popular in aerospace engineering applications providing good strength with superior abrasion-resistant qualities. Typical engineering applications include bearings, valves, hydraulics and engine mounts. Our product is popular in commercial and military aerospace applications and is ideal for fusion welded parts.

Specification & Stock Info

In sheet form, 4130 steel is produced to the AMS 6345 specification in the normalised condition and AMS 6350 in the annealed condition. Specification MIL/AMS-S-18729 also covers both of these conditions. The normalised condition material made to AMS 6345 is slightly harder.

Smiths MRO stock 4130 steel in all standard thicknesses from 0.025" up to 0.125" thickness in large sheets and also cut to size pieces. We also offer in-house processing with a dedicated guillotining service where we cut your sheets to specific sizes to suit your engineering requirements.

Product Features:

    AMS 6345
    AMS 6350

    Fusion welded parts
    Engine seats

    Excellent ductility
    Good workability
    Good abrasion resistance
    Impressive weldability

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4130 Steel Sheet?

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