Proof machined = machined to the final size + machining allowances
The allowances depends on the purchaser standards
- usually in our drawings (in rare cases where we supply finish machined drawing we prefer to supply the drawings to which the component is to be supplied) we mention 3mm allowance on tool point - that means each surface will have 3mm allowance (diameter allowance 6mm, lengths-accordingly)
- However this allowance may vary from component to component (in certain components we ask for more allowance) and company to company.