Guides / Process

Swiss Machining Glossary: Terms Explained in Plain Language

September 24, 2026

Swiss machining has its own vocabulary, and a term that means one specific thing on a quote can sound like ordinary English until it changes the price. This glossary defines the terms that come up most often across an RFQ, a quote and a drawing review, each linked to a full guide for the detail behind it.

A to C

Bar feeder. The machine that holds several meters of round bar and pushes it into the lathe as each part finishes, letting the machine run unattended for hours. Covered in the bar feeders guide.

Bar stock. The raw round bar a Swiss-type lathe feeds and cuts from, as opposed to a casting, forging or pre-cut blank. Bar condition, straightness and diameter tolerance affect both cost and achievable tolerance, covered in the materials guide.

Chucking (single chucking). Cutting several features of a part in one continuous setup without removing and reclamping it. Features cut in the same chucking stay concentric to each other by construction, the main reason Swiss machines hold tight relationships between diameters.

Concentricity. How closely two features share the same center axis. A tight concentricity callout between a front feature and one finished on the sub spindle needs to be called out deliberately, covered in the tolerances guide.

Cross hole. A hole drilled through a part perpendicular to its main axis rather than straight in along the centerline, typically cut with a live tool.

Cycle time. The seconds a machine spends actually cutting one part. At volume, cycle time times the machine rate is most of what sets the price, covered in the cost guide.

D to G

Deburring. Removing the small burr of raised material left at a cross hole, thread start, slot edge or cut off face. Covered in the secondary operations guide.

First article (FAI). The first inspected sample from a new job, measured against the drawing before full production runs, and the report documenting those measurements. Covered in the inspection and quality guide.

Free machining. A material grade formulated to cut fast, break chips cleanly and wear tools slowly, usually through an additive like lead or sulfur. Brass C360, 303 stainless and 12L14 steel are common free machining grades, the last covered in the free machining steel guide.

Gang tool. A style of tool holder that lines up several fixed tools on a slide next to the guide bushing, an alternative to a rotating turret, common on Swiss-type lathes.

Guide bushing. The fixed support the bar slides through right next to the cutting tool, the feature that lets a Swiss-type lathe cut a long slender part without it bending away from the tool. Covered in the pillar guide and the guide bushing versus guide bushing-less guide.

Guide bushing-less mode. Running a Swiss-type lathe without the guide bushing, holding the bar directly in the main collet instead. Suits shorter parts, wastes less bar and accepts standard drawn stock rather than ground bar, covered in the guide bushing guide above.

H to M

Incoterm. A standard international trade term defining who handles shipping, customs and risk of loss at each stage of a shipment, such as EXW or DDP. Covered in the shipping and Incoterms guide.

Kitting. Packaging several different part numbers together as one set, ready for an assembly station rather than arriving as separate shipments. Covered in the packaging and kitting guide.

Lead time. The elapsed time from placing an order to receiving finished parts, covering material sourcing, queue position, setup and the run itself. Covered in the lead time guide.

Live tooling. Rotating, driven cutters mounted alongside a Swiss machine’s fixed turning tools, used to drill off center holes, mill flats or cut slots while the bar is held still. Covered in the live tooling guide.

Lot traceability. The ability to trace a specific finished part back to the material heat or lot it was machined from, required on most medical and aerospace work.

Minimum order quantity (MOQ). The smallest quantity a shop is willing to quote or run economically, driven mainly by how setup cost spreads across the run. Covered in the minimum order quantity guide.

N to R

Non-recurring engineering (NRE). A one time charge covering process development work a shop does once for a part, distinct from a per order setup charge. Covered in the tooling and NRE charges guide.

Passivation. A chemical treatment on stainless steel that removes free iron from the surface and restores its natural corrosion resistant oxide layer, common on medical and food contact parts.

PPAP. Production Part Approval Process, a formal package of evidence an automotive customer requires before approving a part for production, covered in the automotive and EV guide.

Remnant. The short length of bar left over at the end of a run that the feeder cannot advance into another finished part, an unavoidable source of material waste. Covered in the bar feeders guide.

Runout. How much a rotating feature wobbles off its true center axis as it spins, a practical measure of concentricity error.

S

Setup charge. The cost of loading tools, setting offsets and proving a job’s cycle before production runs, charged once per order regardless of quantity. Covered in the minimum order quantity guide.

Sliding headstock. The part of a Swiss-type lathe that holds the bar in a collet and slides it forward along the Z axis, the design feature that gives Swiss-type turning its name. Covered in the pillar guide.

Sub spindle. A second spindle that grips the front of a part once it is cut off from the bar and finishes the back end, letting both ends of a part machine complete without manual handling. Covered in the pillar guide above.

Surface finish. How smooth or rough a machined surface is, usually measured as Ra in microinches or micrometers. Covered in the surface finish guide.

T to Y

Thread whirling. A thread cutting method that spins a ring of cutting inserts around the part rather than a single point tool, used for long precise threads. Covered in the thread whirling guide.

Tolerance stack. The way several individual tolerances combine across an assembly, sometimes adding up in the worst case to more variation than any single dimension shows. Covered in the tolerances guide.

Tool wear. The gradual dulling of a cutting edge through a production run, which drifts the diameter it cuts and eventually needs an offset adjustment or insert change. Covered in the tool wear guide.

Total cost of ownership. The full cost of a sourced part once shipping, duties, inventory carrying cost and quality risk are added to the quoted price, not the quoted price alone. Covered in the total cost of ownership guide.

Work hardening. A material’s tendency to become harder and more difficult to cut where a tool has already passed, common in stainless and nickel alloys and a reason light finishing passes can be counterproductive on these materials.

Y-axis. A machine axis that lets a live tool move off the part’s centerline, reaching a feature positioned away from the axis rather than only straight through it. Covered in the live tooling guide above.

How to use this glossary when reading a quote

A quote that mentions a setup charge, a remnant allowance or a tolerance stack is not padding the price with unfamiliar words. Each term points at a real cost driver covered in depth in the guides linked above. When a line item on a quote does not make sense, the fastest way to get an answer is to ask the shop directly what it refers to and how it is calculated, rather than guessing or assuming it is negotiable.

The terms above also help when comparing two quotes for the same part. A gap between quotes is often explained by a difference in one of these terms, a different bar condition assumed, a different setup charge included or excluded, a different tolerance held, covered in more depth in the comparing quotes guide.

Terms worth asking about even when a quote does not mention them

Some of the terms above matter most when they are missing from a quote rather than present in it. A quote silent on lot traceability, on which secondary operations are included or on what bar condition it assumes is not necessarily hiding something, but it does leave scope open to interpretation. Asking directly whether a quote assumes guide bushing or guide bushing-less mode, what setup charge is included and whether any NRE applies gets you a complete picture before you commit, rather than a surprise once the first invoice arrives.

This matters most on a part you expect to order repeatedly. A one time low volume order tolerates some ambiguity in scope. A part you plan to buy for years is worth the extra few minutes of asking a candidate shop to spell out every term on its quote in plain language, so both sides are working from the same definition before any commitment is made.

Getting parts quoted with clear terminology

Send your drawing through the RFQ form in plain language. You do not need to use the terms above correctly, or at all, to get an accurate quote. We match your part with up to three shops that run Swiss-type lathes and reply within 24 business hours, and any of these terms that shows up on your quote is worth asking the shop to explain in the context of your specific part.

Frequently asked questions

Keep reading

• Gauging Miniature Threads: M1 to M3 and UNM on Turned Parts
• Barrel Plating Swiss Turned Parts: Thickness and Tangling