Leadscrews

Three ways to make the thread

	Thread forming (rolled)	Thread cutting	Thread grinding
Price	Lowest	Medium	Highest
Accuracy	Good	Better	Very precise
Profile	Accurate	Medium accurate	Very accurate
Run-out	Up to 0.1 mm	Up to 0.1 mm	Up to 0.03 mm
Pitch accuracy per metre	300 µm	500 µm	50 µm
Production time, 1000 pcs	1–2 weeks	2–4 weeks	5–9 weeks
Screw materials	MS, EN8, SS303, SS304, SS316	EN8, EN19, WPS, EN24, EN36, SS303, SS304, SS316, SS410, SS420	All ferrous materials

Thread profiles

Profile	Included angle	Forming	Cutting	Grinding
Trapezoidal	30°	Yes	Yes	Yes
ACME	29°	Yes	Yes	Yes
Metric	60°	Yes	Yes	Yes
Square		No	Yes	No
Multi-start (high helix)		Yes	Yes	Yes

The ACME form replaced the square thread, whose straight flanks are difficult to manufacture. ACME comes in three classes: general purpose (G) and centralizing (C), both with a thread depth of half the pitch, and stub ACME, with a shallower thread. Centralizing threads have tighter tolerances and less clearance on the major diameter, so a side load does not make the nut wedge; even so, a lead nut is not designed to carry side loads from a pulley or drive belt.

Standard range and stock

• Single start: 46 sizes, Ø3 to 50 mm, pitch 0.5 to 8 mm
• Multi-start: 18 sizes, Ø5 to 24 mm, 2 to 8 starts, lead up to 30 mm
• Standard length 1000 ±50 mm; right hand, left hand on request
• 3 metre trapezoidal leadscrews in stock: 16x4, 20x4, 25x5, 30x6, 35x6, 36x6
• All tooling is made in-house, which keeps lead times short; standard leadscrews are held in stock
• Ends machined to your drawing (grinding, milling, broaching, threading) to fit bearings and housings