M4 X 40mm Machine Screw Per Pkt

The product is M4 x 25 mm. Available materials include stainless steel, brass, and carbon steel, offering different levels of corrosion resistance, strength, and cost to suit various environments and projects.

Align the parts, insert the screw into a nut or a pre-tapped hole, then tighten with the appropriate driver or wrench. Use a washer if needed to distribute load and prevent pull-through; avoid over-tightening to prevent material damage.

Use cases include construction fastening, furniture assemblies, car door or window frame fittings, deck fastenings, and other metal-to-metal joints where a secure and adjustable connection is required.

Choose stainless steel for maximum corrosion resistance and outdoor or humid environments; brass for non-sparking or decorative applications and moderate corrosion resistance; carbon steel for cost-effectiveness with plating or coating and good strength. Environment, load, and appearance will guide the choice.

These screws are designed for standard screw head profiles and are compatible with common drivers and nuts. Match the driver to the head type (for example, a screwdriver or hex/Allen key) and use a nut driver or wrench for the mating nut if needed.

Yes, especially the stainless steel variant, which offers the best corrosion resistance for outdoor or damp conditions. Brass and carbon steel variants may require additional coatings or indoor use depending on exposure.

Yes. Machine screws are designed to be used with nuts or tapped holes, and you can add washers or thread inserts for better load distribution and grip in softer materials.

The 25 mm length suits fastenings where the combined material thickness provides a solid engagement with a nut or tapped hole. For thicker assemblies, consider longer lengths (for example, M4 x 30 mm); for thinner materials, shorter lengths (such as M4 x 20 mm) may be appropriate.

If you want to compare alternatives, you can check these similar options on Fepy: Stainless steel M4 x 25 mm machine screw: https://fepy.com/product/m4-25mm-machine-screw-stainless-steel; Brass M4 x 25 mm machine screw: https://fepy.com/product/m4-25mm-machine-screw-brass; Carbon steel M4 x 25 mm machine screw: https://fepy.com/product/m4-25mm-machine-screw-carbon-steel

Wear eye protection when driving screws, choose the correct drive to avoid cam-out, keep fingers clear of the work area, and use appropriate torque to avoid stripping threads or damaging the material. Store fasteners in a dry place to prevent corrosion.