Cobalt Content in Carbide Inserts: Why Binder Percentage Is Only One Variable

Questions and answers

What other properties should the datasheet list?

Ask for whatever the supplier measures, such as hardness, density and any toughness or transverse rupture measure, and ask which test method was used for each.

Does the datasheet describe the grade or only the powder?

Ask whether the numbers refer to the finished insert or to a reference sample, and when it was tested.

How consistent is it from lot to lot?

Ask what checks are done on each lot and what records are kept. Ask whether a certificate comes with each shipment and what it contains.

How is the insert attached to the steel?

The joint is part of the product. Ask how it is made and what inspection is done on it.

What do you know from service?

Ask for field feedback, including conditions and surfaces, and be cautious about claims without conditions. Ask whether you can trial a small quantity.

Can I have a sample for independent checking?

If you plan to test, ask the supplier whether they will provide labelled samples and the datasheet for the same lot.

What to do with the answers

The answers only compare if they are in one table.

1. Put each supplier’s answers in a table so you can compare them side by side.
2. Mark any question not answered, and ask again.
3. Decide which properties you care about for your surfaces and your trucks.
4. Trial the most promising options on similar trucks and record the results.

Why not just compare binder percentage?

Because a buyer who compares one number may overlook things that matter more, or may be misled by a claim based on one favourable figure. A fuller picture protects you.

Boundary: No claims are made about how cobalt, hardness or any other property affects service life; ask suppliers for data and test methods.