Screws & Fasteners Buying Guide: Specification, Substrate & RFQ Checklist
Screws, anchors, nuts and specialty fasteners must match the joined materials, hole preparation, load direction and installation tool. Similar dimensions do not guarantee interchangeability.
1. Describe the fastening system
| Family | Key data |
|---|---|
| Machine screw and nut | Thread standard/pitch, length datum, head/drive, nut/washer and clearance hole |
| Self-tapping screw | Diameter, thread form, point, head/drive, pilot hole and substrate thickness |
| Expansion anchor/screw | Anchor body, hole diameter/depth, substrate, expansion method and edge spacing |
| Shelf-support screw/sleeve | Thread, support head/pin, sleeve, panel drilling and shelf interface |
| Special/double-ended fastener | Both-end geometry, installation tool, hidden joint and assembly sequence |
2. Use an unambiguous dimension callout
State metric or inch system, nominal diameter/thread, pitch, under-head or overall length, head form, drive and point. For replacement work, send a measured sample and mating thread or nut.
3. Match substrate and hole preparation
Identify concrete, masonry, timber, particleboard, sheet metal, aluminium or plastic, plus thickness, pilot/clearance hole and edge distance. Anchor capacity is substrate- and installation-specific; request the relevant test method when verified performance is required.
4. Material, finish and compatibility
Specify material/grade, coating and corrosion environment. Consider galvanic compatibility between fastener and joined metals. Colour or a stainless appearance is not material evidence.
Fastener RFQ checklist
| Fastener | Type, standard, thread/diameter, pitch, length, head, drive and point |
|---|---|
| Joint | Materials, thicknesses, hole preparation, edge spacing and mating parts |
| Performance | Load direction, installation torque/method, environment and test standard |
| Finish | Material/grade, coating, colour and compatibility |
| Commercial | Quantity, pack size, tool/nut/washer inclusion, inspection and destination |
Common buying mistakes
- Using “M4” without pitch, length and head/drive.
- Comparing anchor loads across different substrates.
- Confusing overall and under-head length.
- Assuming tools, sleeves, nuts or washers are included.
Browse and enquire
Compare the screws and fasteners collection and send the joint and hole details.
Prepare a fastener quotation
Send the specification, joint, material/finish, pack quantity and destination.