CNC Turning vs Swiss-Type Lathe: Which Fits Your Part

By CHX Metal Engineering Team · Published 2026-11-01

Above roughly 32 mm bar diameter you are on a fixed-head lathe. Below 20 mm and long, a Swiss-type wins because the guide bushing supports the stock at the cut. Our 70 Tsugami machines run bar from 1 mm to 20 mm; the 50 fixed-head lathes take the larger work.

The dividing line is diameter, not price

Buyers usually ask this question the wrong way round. They ask which process is cheaper, and the answer depends on a number they have not given us yet: the bar diameter, and how far the part sticks out of the chuck.

A Swiss-type lathe feeds the bar through a guide bushing that sits a few millimetres from the cutting tool. The tool never pushes against an unsupported cantilever, so a 3 mm shaft 60 mm long comes out straight. Put the same part in a fixed-head lathe and you are fighting deflection from the first pass — you end up with a tailstock, a centre hole, and a second operation.

That is the whole argument, really. Everything else is cost and logistics.

What each machine is actually good at

Where people get caught out

The mistake I see most often is a part designed at 18 mm diameter and 150 mm long, drawn as a single turned piece, quoted on a fixed-head machine because that is what the buyer's last supplier had. It comes back bent. Not much — a couple of tenths in the middle — but enough that the assembly does not go together.

The fix is not exotic. Either move it to a Swiss-type, or accept a two-operation route with a centre. The first option is cheaper if the volume justifies a bar feed setup. The second is cheaper if you need forty pieces.

There is a second trap on the Swiss side: tool clearance. A sliding-head machine has a small working envelope. A part that looks simple on a drawing can need a tool that physically will not fit between the guide bushing and the sub-spindle. We have turned down work for that reason before — not because we could not hold the tolerance, but because the tooling could not reach.

Tolerance expectations on either machine

Both routes hold five microns on diameters and bores when the material behaves. That is not a marketing number; it is what comes off the CMM when the drawing asks for it and the process is stable. Below that you are into a conversation about temperature, fixturing and how many parts you are willing to scrap while the process settles.

Anything not marked critical we run to ISO 2768-m unless the drawing says otherwise. Shops that put tight tolerances on every dimension are paying for inspection they do not need, and the quote reflects it.

Material makes a difference too

Free-machining grades are the reason 303 stainless and H59 brass dominate small turned parts. 303 turns clean and breaks chips; 304 galls and work-hardens if you dwell. Brass runs fast but the chips are worth collecting, which is a sentence I did not expect to write when I started in this trade.

On Swiss machines the bar straightness matters more than on a chucking lathe. A slightly bent bar in a bar feeder will show up as a size drift you cannot explain until you pull the remnant and look at it.

How we quote it

Send the drawing with material, quantity and any finish requirement. We look at diameter and length first, then at the features that need a second operation, and only then at the price. Quotes usually go back within one working day. Small runs are fine — there is no minimum order, one piece is a real order here.

Prototypes take three to seven days depending on material availability. Production runs sit at seven to fifteen days for most turned parts, longer if a finish is subcontracted.