Cut-to-length chrome bar is normally supplied CNC saw cut to the ordered length with about 3 mm allowance, and the ends are left as sawn. Chamfers, threads, center holes and machined end faces are not part of that standard cut; they are quoted from your drawing. Full bars come in 4 m, 6 m, 7.5 m or 8.1 m, and cut lengths start at 200 mm.
How much cutting allowance comes with a cut-to-length chrome bar?
About 3 mm. Yixin Precision Machinery (Changzhou) quotes CNC saw cut-to-length bars from 200 mm with roughly that allowance, and the ends are left as sawn.
The allowance belongs to the saw cut. Anything beyond the cut — a faced end, a chamfer, a thread, a center hole — is end machining, and it is assessed from the drawing rather than folded into the cut length. That split matters at the enquiry stage. An enquiry that gives only the cut length and sawn ends can be quoted directly; one that also calls for a faced and chamfered end goes through a drawing review before it can be confirmed.
Full bars of 4 m, 6 m, 7.5 m or 8.1 m are the alternative. Ordering full bars avoids the saw cut and the allowance altogether; ordering cut lengths gives you the handling benefit but keeps the saw allowance in the length you receive. Which suits you depends on the saw, the bar feeder or the handling equipment at your end of the process.
Cut lengths are confirmed on the drawing and the order, together with grade, diameter, tolerance band and heat-treatment condition. The 3 mm figure is the published saw allowance; it is not a statement about every cut length. If your process needs a defined end condition, put it on the drawing rather than assuming the saw cut includes it.
What do the bar ends look like on delivery?
Sawn. Standard cut-to-length supply leaves the ends as they come off the saw: no machined face, no chamfer and no center hole, unless end machining is written into the order and assessed from your drawing.
That has three practical effects. First, receiving inspection compares the ends with the agreed supply condition, so a sawn end on a sawn-end order is a conforming end, not a defect. Second, if your machine needs a machined face or a chamfer to locate the bar, that requirement belongs in the enquiry, not in an assembly drawing that arrives after the order is placed. Third, packing is built around the same condition: export bars are wrapped in bubble film and packed in wooden cases, with no steel straps on finished bars because they mark the surface.
If you are unsure whether a sawn end is acceptable, send the drawing and describe the first operation you will run on the bar. That is usually enough to decide whether the saw cut is the right supply condition or whether end machining should be quoted as a separate step.
Can the ends be chamfered, threaded or center-drilled?
Yes, but not as part of the standard cut. End machining — threads, chamfers and center holes — is done by long-term partner plants to Yixin's specification and is assessed from the drawing. Yixin's own standard supply is cut to length with sawn ends.
Because the review is drawing-based, the drawing has to show the feature rather than describe it in words. A workable enquiry states which end, or both ends, carries the feature; the chamfer angle and size; the thread designation and length; the center hole type and size; and the datum from which the feature is measured. If a chamfer appears only as a note on the assembly drawing, restate it on the bar drawing so it can be quoted without a round of questions.
Two conditions are worth planning for. End machining is an extra step outside the standard cut-to-length flow, so it is quoted as a separate operation and confirmed with the order. And because the work is carried out by partner plants, the drawing and the specification travel with the order — keep the revision you want quoted, and check that the machined ends on delivery match that revision.
Which lengths, diameters and lead times apply?
Cut lengths start at 200 mm and run up to full bar lengths of 4 m, 6 m, 7.5 m or 8.1 m. The saw allowance on a cut length is about 3 mm, and the ends stay as sawn unless end machining is ordered.
| Item | What is supplied |
|---|---|
| Full bars | 4 m, 6 m, 7.5 m or 8.1 m |
| Cut to length | CNC saw cut, from 200 mm |
| Saw allowance | about 3 mm |
| Ends | left as sawn |
| End machining (threads, chamfers, center holes) | quoted from the drawing; performed by long-term partner plants to Yixin's specification |
| Diameter | Standard range Ø4–140 mm; up to Ø200 mm made to order |
| Diameter tolerance | selected from the published bands and fixed on the order; 0/−0.02 mm is typical for linear bearings |
| Lead time | cut-to-length from stock 3–5 days; non-standard diameter 7–10 days; custom heat treatment 10–20 days |
Diameter coverage is not identical across the product range. The 42CrMo Q&T Chrome-Plated Bar, for example, is made to order from Ø8–100 mm. Where you need a specific band, name the product and the finished diameter on the enquiry, and the tolerance is confirmed with the order.
How do I check cut-to-length bars on receipt?
Compare four things against the order: the goods, the ends, the length and the packing. A short checklist keeps the inspection factual.
| Check | What to verify |
|---|---|
| Order line | product name, grade, diameter and tolerance band, cut length, heat-treatment condition, quantity |
| Ends | sawn ends unless end machining was ordered; machined features match the quoted drawing revision |
| Length | measured against the ordered cut length, with the saw allowance in mind |
| Packing | bubble film and wooden cases for export, no steel straps on the finished bars |
| Documents | steel mill certificate for each heat, commercial invoice, packing list, certificate of origin per order |
If a cut length looks short, check the order line before rejecting the piece: the ordered length, not the allowance figure, is the reference. Third-party testing can be arranged on request for an order; it is not part of the standard specification. A steel mill certificate is supplied for each heat.
What to put in your RFQ
- Cut length in millimeters, stated as the length you want to receive, and the quantity.
- Whether sawn ends are acceptable, or whether the ends need machining.
- The end features, if any: chamfer angle and size, thread designation and length, center hole type and size, and which end carries them.
- Product name, grade, diameter and the tolerance band you need.
- Heat-treatment condition and surface condition, so the correct catalogue product is quoted.
- Whether you are buying full bars or cut lengths; if full bars, the bar length.
- Packing and marking instructions: buyer's brand can be printed on the packing only, not on the bars.
- Documentation and terms: mill certificate, certificate of origin, third-party testing arranged on request, and the applicable Incoterm.
Summary
For cut-to-length chrome bar, the allowance question has a short answer: about 3 mm on a CNC saw cut, ends left as sawn, and cut lengths from 200 mm up to full bars of 4 m, 6 m, 7.5 m or 8.1 m. Chamfers, threads and center holes are end machining, assessed from the drawing and performed by long-term partner plants to Yixin's specification. The clean way to specify is to separate the two decisions — the cut length you receive, and the end condition you need — and to show both on the drawing that goes with the order.