Identify the thickness basis
BMT describes the steel substrate before coating. TCT includes the substrate and coating layers. [1]
Ask whether the quoted thickness is BMT or TCT. For painted material, ask which layers are included. A number labelled only ‘thickness’ leaves this comparison unresolved.
Compare the same specification
Before comparing prices, put both offers into a common requirement sheet. Record the thickness basis, units, steel grade, coating designation and requested tolerance. Ask the supplier to confirm any proposed difference rather than treating two nominal thickness numbers as equivalent.
Thickness alone does not establish a member’s load or span capacity. Use the responsible designer’s requirements and the offered product documentation. [2]
Prepare the quotation request
For floor decking or purlins, attach the section drawing, revision, cut lengths and quantities. For sandwich-panel faces, identify the face-sheet thickness separately from overall panel thickness. Request the agreed material or inspection documents. Mark unknown requirements ‘To confirm’.
This is a terminology guide, not confirmation of a ZY product configuration. Offered specifications and documents are agreed in the quotation.
Sources and scope
These sources explain terminology. They do not certify a ZY product or establish the standards applicable to your project.
Related product requirements
Steel quotation comparison sheet
Fill in the same requirements for each supplier; mark unknown items To confirm. Email drawings and the completed sheet to [email protected].
Download editable comparison sheet