Screw Machine
A screw machine is an automatic production lathe built for repeated manufacture of turned parts from bar stock; it may be single-spindle, multi-spindle, cam-driven, CNC or hybrid.
How Screw Machine works
- Bar stock feeds through one or more spindles and tools perform turning, drilling, forming, threading and cut-off operations.
- On a multi-spindle machine, work advances through several stations so different operations occur concurrently.
- Cam machines prioritize repeatable high-volume production; CNC and hybrid designs add programmability and process flexibility.
- Attachments, feed system, collets, cams, tooling and operator knowledge are part of the production asset—not merely accessories.
What to compare
| Architecture | Single versus multi-spindle; cam, CNC or hybrid control. |
|---|---|
| Capacity | Maximum round/hex stock, feed length and finished-part envelope. |
| Operations | Cross-working, back-working, threading, forming and secondary-operation capability. |
| Changeover | Cam/tooling availability, setup time and suitability for the part mix. |
| Support | OEM/rebuilder parts, manuals, training and skilled-operator availability. |
Used-equipment inspection checklist
Verify the machine
- Run the machine at production speed using representative stock.
- Check spindle condition, indexing, feed and cutoff behavior.
- Inventory cams, collets, attachments, gears and manuals.
- Review guarding, mist control and current safety configuration.
- Value the machine with its transferable production package clearly itemized.
Verify the transaction
- Match the serial number and configuration to the seller's description.
- Identify every included and excluded accessory in writing.
- Confirm power, air, coolant, foundation, rigging and relocation requirements.
- Record a time-stamped operating demonstration and measured result.
- Price missing service, software, tooling and recommissioning before comparing offers.
Why this term matters in the used-machine market
Search results and listings often compress a complete production system into one label. Buyers should translate that label into capacity, condition, control generation, included tooling, serviceability and demonstrated output. Sellers improve credibility by disclosing those facts instead of repeating a brochure headline.
Market value is also specific to timing and buyer fit. A capable machine can trade poorly when its configuration is hard to relocate, support or redeploy; a common platform with documented maintenance, current controls and proven output may attract a wider buyer pool.
Related machine-tool terms
Frequently asked questions
Why is it called a screw machine?
The name comes from early automatic production of screws and similar turned parts, but modern machines produce a much broader range.
When does multi-spindle make sense?
It is strongest where stable, repeatable volume justifies setup and multiple simultaneous operations reduce cycle time.
Sources and further reading
Source roles are explicit: linked organizations describe their own products, programs or technical guidance. The Machine Blue Book independently organizes and interprets that material for education and used-equipment due diligence. A citation is not an endorsement, sponsorship or guarantee.
- Davenport Machine — Multi-Spindle Screw Machines. OEM explanation of multi-spindle screw-machine architecture and production use. Reviewed September 26, 2026.
- IMTS — IMTS Technology Sectors. Primary classification of metal removal, quality, automation, software, tooling and workholding sectors. Reviewed September 26, 2026.
See the complete source register, research methodology and editorial standards.