Machine lead screw worn out or unobtainable? When the traversing screw on a lathe, mill, press or vice is worn, seized or discontinued, it has to be cut to match — the right thread form, pitch, number of starts and hand. We single-point machine it to your drawing or straight from the worn original.
What Is a Lead Screw?
A lead screw (or power screw) converts rotary motion into linear motion through a matching nut — the traversing and cross-feed screws on a lathe or mill, a press or jack screw, a vice or clamp screw, or a linear actuator. Unlike a fastening bolt it uses a power-thread form — ACME or trapezoidal — for strength, smooth travel and wear life. Because the screw and nut work as a pair, the thread form, pitch, lead, number of starts and hand all have to match, which is exactly why a worn one can't just be swapped for a catalogue bolt.
Thread Forms We Cut
ACME (29°)
Imperial power thread (ANSI/ASME B1.5) — the classic lathe and machine-tool lead screw form.
Trapezoidal (30°)
Metric power thread (ISO 2904 / DIN 103), e.g. Tr20×4 — the metric equivalent of ACME.
Square thread
Highest-efficiency power thread for presses and jacks where drag must be low.
Modified square / buttress
One-direction load forms for presses, clamps and vices.
Multi-start leads
2-start, 4-start and more for faster linear travel per turn.
Left-hand & non-standard
LH threads and odd or obsolete pitches — single-point cut, so no tooling limit.
ACME vs Trapezoidal — Which You Need
| ACME | Trapezoidal (Tr) | |
|---|---|---|
| Thread angle | 29° | 30° |
| System | Imperial (inch) | Metric |
| Standard | ANSI/ASME B1.5 | ISO 2904 / DIN 103 |
| Called out as | e.g. 1/2"–10 ACME | e.g. Tr20×4 |
| Typical use | Imperial & older UK/US machines | Metric machinery, newer builds |
Not sure which your machine uses? Send the worn screw or a mating nut and we identify the form, pitch and hand for you.
What We Need to Quote
| Detail | What to tell us |
|---|---|
| Thread form | ACME / trapezoidal / square — or "match my sample" |
| Diameter & pitch | Nominal Ø and pitch (or TPI), e.g. Tr20×4 or 3/4"–6 ACME |
| Starts & hand | Single or multi-start; right- or left-hand |
| Length | Overall length and any plain journal / bearing ends |
| End features | Turned journals, keyways, threaded or drilled ends |
| Nut | Do you need a matching nut cut too, and in what material |
Materials — Screw & Nut
| Part | Materials | Best for |
|---|---|---|
| Lead screw | Carbon steel (EN8/C45), alloy steel, stainless 303/304 | Strength, wear, corrosion resistance |
| Nut | Phosphor bronze / gunmetal, brass, acetal (POM) | Low-friction wear; acetal for quiet self-lubricating light duty |
We pair the screw and nut to your load, duty cycle and environment — a bronze nut for durable machine-tool duty, or an acetal nut for smooth, self-lubricating light travel.
Applications
- Lathe and milling machine lead, feed and cross-slide screws — replacement and restoration
- Press, jack and clamp screws; vice screws and bench-vice spindles
- Linear actuators, adjusters and positioning mechanisms
- Vintage and obsolete machinery where the original screw is no longer made — see replacement parts and obsolete threads
Only have the worn screw? Send it (and the nut, if you have it). We gauge the form, pitch, starts and hand, restore the worn thread to its original profile, and machine a new screw — and a fresh nut if needed. No drawing or CAD required; more on how we reverse engineer from a sample.
Custom & Replacement Lead Screws — Honestly Scoped
We single-point cut ACME, trapezoidal and square threads on the lathe. That suits replacement and restoration lead screws for manual machines, presses, vices, jacks and general power transmission — a straight functional screw that matches your original and runs smoothly in its nut. It is not micron-class thread-ground precision for high-accuracy CNC positioning; if that's what you need, we'll say so. For everything from a seized lathe lead screw to an obsolete press screw, this is exactly what we make. See also our threaded rods & studding for straight fastening threads and non-standard threads.
Frequently Asked Questions
A threaded rod that converts rotary into linear motion through a matching nut — the traversing screw on a lathe or mill, a press or jack screw, a vice screw or an actuator. It uses a power-thread form (ACME/trapezoidal), and its pitch, lead, form and hand must match the nut.
Yes — our main lead-screw work. Send the worn original (and nut if you have it); we gauge form, pitch, starts and hand, restore the worn thread to its original profile, and machine a new screw — and a fresh nut if needed. No drawing or CAD required.
ACME (29° imperial, ANSI B1.5), trapezoidal (30° metric, ISO 2904/DIN 103, e.g. Tr20×4), square and modified-square, plus non-standard pitches and multi-start leads — single-point cut, so odd or obsolete pitches are fine.
Yes — right- and left-hand, single or multi-start (2-start, 4-start and more) for faster travel per turn. Tell us the lead and travel you need.
Screws in carbon steel (EN8/C45), alloy steel or stainless (303/304); nuts in phosphor bronze/gunmetal, brass, or acetal/POM. We pair them for your load, duty and environment.
We single-point cut the thread — ideal for replacement and restoration screws for manual machines, presses, vices and general power transmission. This isn't micron-class thread-ground precision for high-accuracy CNC positioning; for a functional replacement that matches the original, it's exactly right.
One piece, no tooling charge. Quote in 24 hours; typically 1–3 weeks by length, form and quantity, plus tracked worldwide shipping. Very long screws are quoted case by case.
Get a Lead Screw Quote
Send the form, pitch & length — or the worn screw. We reply within 24 hours.
// Qty & price
1 pc
Sample price
Match & confirm fit
2–10
Unit price drops
Setup cost shared
10+
Best price
All tiers quoted upfront
- →No distributor — you pay the maker directly
- →CAD saved after first order — reorder anytime at lower unit price