Choosing the correct material for your components

Choosing the correct material for your components

Choosing the appropriate material for your components is vital to ensure that the product functions correctly; but the decision is not always easy and careful consideration is required.

There are numerous factors which can impact the overall decision.

Material Properties to look out for:

Tensile Strength

This is the simply the amount of force which can be applied to the material without it snapping. If the application of the component means it will come under stress, or significant force, then selecting a grade with higher tensile strength will offer more durability.

Machinability

Some materials may look great on paper when analyzing the chemical make-up; but if they then cannot be easily machined it could become problematic; especially on intricately designed components. A less machinable material may require specialist tooling; and increase the cycle time on the machine; which will add to the overall cost and lead time.

Weldability

If the components are part of an assembly which require welding operations, then the material needs to be of a suitable weldable quality. If you do still need to choose a material that is less weldable, it may require a specialist welder with more expertise to be able to complete this, which would come at an added cost. It may also take longer for the welding operation, again increasing the expense.

Ductility/Formability

A material with higher ductility can be more easily shaped; and a material which is less formable can’t be bent easily and will be prone to snapping.

Surface Finish

If your component part is on show, you may want it to have a more aesthetically pleasing finish. Some materials, such as stainless steel, offer more desirable finishes for higher end application. Sometimes, choosing a cheaper grade, but having an additional finishing operation such as powder coating, or plating, can still create the desired finish.

Cost

Although the parts themselves must function as required, sometimes the budget can sway the overall decision. Sometimes, selecting a lower grade material can offer very similar chemical composition and also be a cheaper alternative; without compromising on the overall quality and functionality.

Material Summary – Metals:

Cold Rolled Steels

Numerous grades offering different properties Easier to control tolerances due to the shaping process before cooling High strength grades Can tolerate high loads Suitable for heavy wear Cost effective for automotive, industrial and construction applications May require extra surface treatment or finishes to prevent rust

Stainless Steels

Numerous grades offering different properties; such as water resistance, food grade etc. Resistance to extreme temperatures Corrosion resistance Easy to work with and machine Aesthetically nicer finish Good for food grade applications; automotive, and chemical industries

Aluminium

Often a low cost and sustainable option Good corrosion resistance Durable and ductile Typical used in industries such as pharmaceutical, food, automotive and construction

Copper

Good resistance to water and corrosive chemicals Formable and ductile – so has diverse applications Commonly used in electronics, construction and automotive industries Also has some antimicrobial properties so could benefit the medial and food industries

Brass

Good corrosion resistance Solderable and easy to bend and form into desired shapes Attractive finish Commonly used in fasteners and valves in multiple industries

Material Summary – Plastics:

Polypropylene

Doesn’t react to acid, and resistant to corrosion and chemical leaking Can be moulded into shape easily as it turns to liquid at it’s melting point Malleable so can bend without snapping High tensile strength to withstand heavy loads Used in multiple applications across many industries

Nylon

High resistance to abrasion Can be mixed with glass or carbon to improve performance Often less expensive than metals Lightweight yet durable, with high tensile and impact strength Nylon has many applications in almost any industry

Delrin

High tensile and impact strength Good versatility and can be easily shaped and machined Good resistance to moisture, solvents and many other chemicals Often used to make bearing, bushes, gears, rollers etc. in automotive & mechanical sectors.