When you’ve been ordering the same component for years, some of the detail can get taken for granted. Your supplier knows which finish is acceptable, how the part fits into the assembly and why one particular dimension needs careful attention. A new supplier needs that information too, and it may not all be on the drawing.

In its article Finding UK capacity, Qimtek discusses how difficult it can be for buyers to find specialist UK manufacturers, even when the capability is there. Once you’ve found a company worth talking to, a thorough discussion about the component will help you decide whether to move the work.

Make sure the drawing tells the whole story

Start with the latest approved drawing. That sounds obvious, but an old file attached to a new enquiry can cause problems before anyone has cut a piece of material.

Check it against what’s actually being supplied. Has a dimension changed? Was a different finish agreed? Perhaps your current supplier has been working to an amendment that never made it back onto the drawing.

Explain how the component is used, particularly where it mates with another part. If a fit has proved troublesome in the past, say so. It gives the new supplier something useful to investigate before production starts.

Specify the material properly

“Stainless steel” isn’t a complete material specification. Give the required grade and flag any certification or traceability requirements when you first enquire.

If you’re open to an alternative, explain why. The supplier can discuss the machining implications with you, but a material change still needs to be suitable for the application and approved by whoever is responsible for the design.

Include coatings, heat treatments and other finishing processes. Where these affect dimensions, make clear whether the drawing requirements apply before or after treatment.

Decide what you need from a sample

An existing part can be useful, especially when it helps explain an assembly or a feature that’s difficult to show on paper. A worn component, though, needs treating with care. It may no longer represent the dimensions you want reproduced.

If you need samples before approving a production run, agree how you’ll assess them. Will you check the dimensions, test the fit in an assembly or put the part through a working trial?

Allow time for this. Sample approval belongs in the delivery schedule, including the time your own team needs to do it.

Be clear about when the parts are needed

Give the supplier a required delivery date and explain what depends on it. There’s a difference between replenishing stock and supplying a component needed for a booked production run.

Ask what the quoted lead time covers. Material, tooling, sample approval and outside processing can all affect the schedule. If a smaller first delivery would help, discuss that early rather than waiting until the full batch is nearly due.

Where possible, keep enough stock to cover the handover. A little overlap gives you room to resolve questions without putting production under pressure.

Read the assumptions behind the price

Check that each quotation covers the same drawing revision, material, quantity and inspection requirements. Look for separate setup or tooling charges, and clarify delivery costs.

For repeat components, share your likely annual usage as well as the immediate order quantity. It helps the supplier understand the work and discuss sensible production arrangements with you.

Talk to Bon Precision about your component

At Bon Precision Engineering, we manufacture precision turned parts at our Northamptonshire workshop using Star and Citizen sliding head CNC machines. We produce bespoke fasteners, threaded inserts, pins and spacers for customers across the UK.

If you’re considering a change of supplier, send us the drawing, quantities and required delivery date. Tell us about any issues with the existing part too. We’ll review the requirements with you and discuss what we can offer.

Contact Bon Precision Engineering to discuss your turned parts.