Trapezoidal Lead Screws Made to Order: Ø4 to Ø24 from Our Range, Ø60 to Ø300 to Drawing, With the Nut to Match

Need a trapezoidal lead screw in a lead, length or end shape the catalogue does not carry? Catalogue Tr thread comes as plain bar in the ISO 2904 sizes, mostly single start, in stock lengths, and the nut is a separate hunt. We make trapezoidal lead screws from Ø4 to Ø24 in 110 lead, pitch and start combinations, up to 36 starts, six sizes in left-hand, cut to your length with turned journals, keyways, end threads, flats and circlip grooves, and the bronze or plastic nut that runs on them, from one piece; Ø60 to Ø300 to your drawing. No drawing needed: a photo with a rule, the measurements in a message, the old part or its part number is enough; we draw it, you approve, we machine. Get a quote →

Four trapezoidal lead screws we made, each with its nut

EKINSUN LTD is a custom parts manufacturer that makes trapezoidal lead screws and the nuts that run on them to the buyer's drawing, from one piece. The photos are from our own orders: a bronze round flange nut with stepped journals at both ends, a flange nut with a keyway on the drive end, a stainless screw with a plastic anti-backlash nut, and a bronze block nut with a short journal and a small metric thread. No customer part numbers are shown; every one of them started as a drawing or a photo of the old screw.

Trapezoidal lead screw, Tr screw, power screw, threaded spindle: one part, many names

The part is a shaft with a 30° trapezoidal thread that moves a nut along it. Machine builders call it a lead screw or leadscrew, textbooks a power screw or translation screw, the drive trade a threaded spindle or screw spindle, and the callout is Tr followed by outside diameter and lead, Tr20×4 for a single start, Tr20×8P4 for two starts. In German it is a Trapezgewindespindel or Gewindespindel, in French a vis trapézoïdale or vis de transmission, in Italian a vite trapezoidale, vite di trasmissione or albero filettato trapezoidale, and with several starts a vite a più principi. The inch cousin with a 29° flank is the ACME screw, on its own page together with replacing a worn machine screw from the old one. Whatever it is called on your side, the order is the same six things: outside diameter, lead, pitch, starts, hand, length, plus the ends and the nut.

Ø4 to Ø24: what our range covers

The table below is our own range, one row per nominal diameter; the size chart lists all 110 sizes with root diameter, the largest diameter an end can be turned to, and the efficiency with a plastic or a bronze nut. Outside diameters are as produced: inch blanks such as 9.53 mm (3/8 in), 12.7 mm (1/2 in) and 22.23 mm (7/8 in) sit inside the metric groups, and the exact figure is confirmed on the drawing before machining.

Nominal	Outside Ø as produced	Leads	Pitches	Starts up to	Left-hand in the range	Sizes
Ø4	4.2, 4.71	1 – 2 mm	1	2	to order	2
Ø5	4.71, 5.4, 5.71, 6	5 – 20 mm	1.25, 2.5	16	to order	4
Ø6	6, 7.4	1 – 25 mm	1, 1.25, 1.5, 2, 2.25, 2.5, 4.5	20	to order	9
Ø8	8, 8.2, 8.6	1 – 30 mm	1, 1.25, 1.5, 2, 2.5, 3, 4	24	lead 1 mm	9
Ø10	8.9, 9.53, 10, 10.1	1 – 50 mm	1, 1.25, 1.4, 1.5, 2, 2.5, 3, 5	28	to order	17
Ø12	11.9, 12, 12.2, 12.62, 12.7, 12.8	2 – 45 mm	1.25, 2, 2.5, 3, 3.2, 5	36	to order	16
Ø14	13.62, 13.9, 14, 14.3	2 – 30 mm	2, 2.5, 3, 4, 5	6	lead 3 mm	9
Ø16	15.9, 16, 16.5, 17	2 – 90 mm	2, 2.29, 2.5, 3, 4, 5	18	lead 3 mm	11
Ø18	17.9, 18, 18.7, 18.8	2 – 100 mm	2, 3, 4, 4.5, 5, 6	20	lead 4 mm	9
Ø20	20	2 – 45 mm	2, 3, 4, 5, 6	9	lead 4 mm	8
Ø22	21.54, 22, 22.23	3 – 50 mm	2, 2.5, 3, 4, 5	10	lead 5 mm	11
Ø24	24, 24.3	3 – 55 mm	3, 5	11	to order	5

Above the range: trapezoidal screws from Ø60 to Ø300, large pitch and multi-start, are made to your drawing. Standard Tr sizes in the range carry ISO 2903 tolerance class 7e on the pitch diameter, the class the ISO tables call medium.

What buyers ask for, and what we do about it

The situation	What we make	Details that go on the drawing
A screw of a given size, cut to my length	Any length; the screw is cut from the range and both ends finished	Outside diameter, lead, pitch, starts, hand, overall length
Bearing journals, a keyway, a thread on the end	Turned journals to h6 or k6, keyways to DIN 6885, metric end threads, flats, circlip grooves	Each end as a small sketch: diameters, lengths, fits; the largest end diameter is in the chart
Faster travel per turn	Multi-start screws, 2 to 36 starts, leads to 100 mm per turn	Lead and starts; see the multi-start page for the 50 % line
A left-hand screw	Left-hand in six chart sizes, other sizes to order	LH after the callout, and whether the nut is left-hand too
The nut as well, or only the nut	Round flange, two-flat flange, block, plain round, plastic anti-backlash	Nut form and mounting; see the nut page
The old screw is worn or the machine is out of production	Made from the worn original, thread form gauged from the unworn end	Send the screw and the nut; see replacement lead screws
Larger than Ø24	Ø60 to Ø300, large pitch, multi-start, to drawing	Drawing or the old screw; quoted case by case
Stainless instead of steel	304 stainless screw, plastic or bronze nut	Grade and where the screw lives

Ends: journals, keyways, threads, flats, circlip grooves

A lead screw is never just thread. One end sits in a bearing, the other takes a handwheel, a coupling or a motor, and the nut has to be able to run off the thread to be fitted. The chart gives, for every size, the largest diameter an end can be turned to; below that, any of the following is machined on the same screw.

End feature	What to specify	Limit
Plain journal	Diameter and fit, h6 for a bearing seat, length, shoulder	Diameter at or below the chart's largest end Ø for that size
Stepped journal	Each diameter and length in order from the thread outward	Same limit for the first step
Keyway	Width and depth to DIN 6885, length and position; the key if we should supply it	Journal diameter sets the key size
End thread	Metric callout, length, chamfer; for a locknut or a coupling	Thread major diameter below the journal diameter
Flat or D-cut	Width, length, position for a set screw or a handwheel	—
Circlip groove	DIN 471 groove for the shaft diameter, position	—
Cross hole	Diameter and position for a pin or a handle	—
Square or hex drive	Across flats and length	Across corners below the journal diameter

Materials: bearing steel first, then stainless and carbon steel, and the nut to match

Material	When it is the right choice	Note
Bearing steel 100Cr6 (GCr15, SAE 52100)	The standard for the whole Ø4 to Ø24 range: machine tools, semiconductor equipment, instruments, conveyors	Screw only; the nut is a different metal
Stainless steel 304 (1.4301)	Wet, washdown, food and lab equipment	The screw with the plastic nut in the photo
Carbon steel C45 (1.0503)	General machinery where bearing steel is not called for	Also for large screws to drawing
Aluminium 6061	Light hand-feed and instrument screws where weight matters more than wear	With a plastic or bronze nut
Bronze nut	Machine-tool duty, long life, load	The bronze column of the chart
Plastic nut (POM)	Quiet, self-lubricating, higher efficiency, light load	The plastic column of the chart; anti-backlash version with spring
Brass nut	Light duty, instruments, water	On request

How screw and nut are checked

Standard Tr sizes are made to ISO 2903 class 7e on the screw pitch diameter, and the chart carries the outside and root diameters as produced. Journals are measured against the fit on the drawing, keyways against the key. Screw and nut ordered together are run together before packing, so the pair meshes before it ships, and a material certificate goes with the parts on request.

Price, lead time, delivery

There is no list price for a lead screw made to your length and ends; a single piece starts from €25 and is quoted within 12 hours from the callout: outside diameter, lead, pitch, starts, hand, length, the ends, and whether a nut goes with it. One to a few dozen pieces ship in 5 working days, 50 to 500 in 15 working days, delivered DDP to your door with duties in the quote. The first piece is the sample; repeat orders run to the same drawing, and 500-piece and 1,000-piece runs are priced lower per piece. The screw is bearing steel unless the order says stainless 304 or carbon steel C45; the nut is bronze unless the order says plastic; the grades go on the drawing.

Where the lead screw catalogue stops

What you need	In the catalogue?	What to do
Plain Tr bar, ISO 2904 size, single start, stock length	Yes	Buy it there, or ask us, we may have the size
A Tr screw cut to length with journals, keyway and end thread	No	Made to order; the parts in the photos
A 4-start or 8-start screw in a Ø10 or Ø12 size	Rare	In our range; see the chart
A 20-start or 36-start screw	No	In our range: Ø18 × 100 with 20 starts, Ø12 × 45 with 36 starts
A left-hand Tr screw with its nut	Rare	Six sizes in the range, others to order
A flange nut drilled to my housing	No	Made to your hole circle
An anti-backlash plastic nut for an existing screw	Rare	Made to the screw you send
A Ø60 to Ø300 multi-start screw	No	Made to drawing

Related lead screw pages

Frequently asked

Can you make a trapezoidal lead screw to my drawing, with the nut?

Yes. Screw and nut are one order: the screw from the chart size or to your callout, cut to length with the journals, keyway, end thread, flats or circlip grooves your drawing shows, and the nut as a round flange, two-flat flange, block, plain round or plastic anti-backlash nut. The four photos above are pairs we made that way.

Which sizes do you make?

Ø4 to Ø24 from our own range: 110 combinations of outside diameter, lead, pitch and number of starts, leads from 1 mm to 100 mm per turn, up to 36 starts, six sizes also in left-hand. Larger screws, Ø60 to Ø300 with large pitches and multi-start threads, are made to your drawing. The full list is on the size chart.

Can I get only one lead screw made?

Yes. Minimum order is one piece and a single screw starts from €25; ten pieces share the same setup. Quote within 12 hours, 5 working days for one to a few dozen, DDP to your door.

What material are the screws?

Bearing steel, 100Cr6 (GCr15, SAE 52100), as standard for the whole Ø4 to Ø24 range. Stainless 304 and carbon steel C45 on request, as on the screw with the plastic nut in the photo. Nuts are bronze as standard and plastic where the efficiency column of the chart is the one you need.

How do I order a lead screw without a drawing?

Write the callout: outside diameter, lead, pitch, starts, hand, length, and what each end must be, for example Ø12 × 3, single start, 400 long, one end turned to Ø8 h6 with a 3 mm keyway, bronze flange nut. A photo of the old screw with a rule, or the old screw itself, does if any of those is unknown. The drawing comes back with the quote and machining starts after you approve it.

Who makes trapezoidal lead screws in small quantities, and how much do they cost?

EKINSUN makes them from one piece; a plain screw starts from €25 and is quoted in 12 hours. Length, the end features and the nut set the price, and 500 or 1,000 pieces are priced lower per piece than the sample.