Fabrication & buying
How to specify thickness, dimensions, tolerances and quantity
An order checklist to help suppliers quote against the same requirements.
Use consistent units, distinguish raw material from finished dimensions, and identify critical tolerances.
Describe the product form
For sheet, state thickness × width × length. For round tube, state outside diameter × wall × length. For rectangular tube, give section dimensions, wall and length. Supply finished-part drawings and explicit quantity units.
Nominal thickness and acceptance
Pair the specified thickness with an applicable standard or agreed tolerance. Define the measurement and acceptance requirements instead of relying on informal descriptions such as “full thickness”.
Layout, allowances and finished size
Clarify whether you need full sheets, blanks or formed parts. Mark grain direction, folds, holes, film and visible faces. Finished dimensions are not a substitute for an agreed flat pattern.
Use this enquiry outline
Product: ___; grade/standard: ___; thickness/tolerance: ___; dimensions: ___; finish/colour/grain: ___; quantity/unit: ___; drawing revision: ___; destination and preferred schedule: ___. Mark unknown items “to discuss”.