CNC Spring Formers vs Cam Spring Machines: A Sizing Guide for Real Production Floors

Most spring buyers I talk to do not really want a machine. They want a stable output number on the shop floor at 8 a.m. every morning. That is the angle I will use here: which CNC spring former for belleville spring production, which tension spring machine, and which cam or camless platform actually fits your wire diameter and tolerance target.

Dongzheng Spring Machine has been building spring forming equipment in Dongguan since 2004. We run 150+ units of annual capacity, and outside China we have shipped 150+ units to 15+ countries, with Vietnam at 40+, Brazil at 10+, and Indonesia and Korea at 5+ each. That footprint is the reason I prefer to talk in machine counts instead of marketing slogans.

Where The Decision Actually Starts

Every spring machine decision starts with three numbers: wire diameter, tolerance, and batch length. Once those are clear, the cam vs camless question answers itself.

Parameter	Cam Spring Machine	Camless Spring Machine
Wire diameter range covered	0.2 - 6.0 mm	0.1 - 4.5 mm
Setup change time	15 - 40 min (cam change)	1 - 5 min (program only)
Best for	Long runs, one part repeated	Mixed batch, short runs, samples
Tooling cost	Higher per shape	Lower, mostly quill tooling
Typical part family	Compression, simple torsion	Tension, complex torsion, special pitch

If you are buying a tension spring machine for varied wire diameters and frequent job changes, camless usually wins. If you run one belleville spring part all week on the same coil, a cam platform gives you better steady-state stability.

Reading Our Model Line Without The Brochure Language

Our full range, with the wire diameter each one actually handles in production:

• HSM-CNC08 Spring coiling machine: 0.08 - 1.0 mm

• HSM-CNC20 Cam Spring Machine: 0.2 - 2.0 mm (flagship, 100+ units running worldwide)

• HSM-CNC30 Spring Coiling Machine: 0.8 - 3.0 mm

• HSM-CNC40 Cam Spring Machine: 1.8 - 4.5 mm

• HSM-CNC60 Cam Spring Machine: 2.0 - 6.0 mm (two variants, with or without wire rotary)

• HSM-CNC1008 Camless Spring Machine: 0.1 - 1.0 mm

• HSM-CNC1025 Camless Spring Machine: 0.2 - 2.5 mm

• HSM-CNC1045 Camless Spring Machine with wire rotary: 1.8 - 4.5 mm

The HSM-CNC20 is the one I bring up first because it is the model most customers benchmark us against. It covers the middle of the wire diameter spectrum, and 100+ units in the field is enough sample size to talk about real behavior, not brochure behavior.

A Quick Tolerance Reality Check

When a customer tells me they need ±0.01 mm, I always ask what wire, what free length, and how many parts per shift. On our HSM-CNC20 platform, a tension spring machine setup running 1.0 mm stainless wire at a stable temperature can hold ±0.01 mm over a full shift once the program is locked in. That is not a theoretical number, it is what we see in Vietnam on a customer line that has been running since 2010.

Spec	Typical Request	What HSM-CNC20 Delivers
Wire diameter	0.3 - 2.0 mm	0.2 - 2.0 mm verified range
Length tolerance	±0.01 mm	±0.01 mm steady state
Daily output gain	30%+ vs old machine	35% measured at one Vietnam site over 8 months
Program storage	100+ parts	Yes, on controller

Three Real Shop Floor Stories

Vietnam, 2010. A spring maker in Vietnam bought an HSM-CNC20. After 8 months on the line, daily output on their tension spring part was up 35% versus the unit they replaced, and length tolerance stayed at ±0.01 mm. That machine is still on the floor.

Brazil, 2022. A customer took delivery of 2 units of HSM-CNC20. They were added to our WeChat service group at installation. To date, they have never raised a service ticket. No repairs, no remote interventions. That is the boring case I like, because boring means the machine is doing its job.

Shenzhen, 2026. A new customer bought 2 units of HSM-CNC20 plus an HSM-CNC08 press spring machine. Their setup technician came from a plant where he had run machines from several brands. Without being prompted, he told us he specifically liked Dongzheng machines because they are stable, durable, and easy to set up. That comment matters more to me than any spec sheet, because the person adjusting the machine all day is the one who actually knows.

Vietnam, March 2026. Another customer, after seeing our machine at a competitor's site, compared it to the tension spring machine he already owned. The stability difference was visible enough that he placed an order for 1 unit of HSM-CNC20 immediately.

Choosing For Belleville And Disc Springs Specifically

Belleville springs look simple, but the load curve is sensitive to thickness uniformity and cone angle. For belleville spring product work under about 2.0 mm thickness, the HSM-CNC20 is usually the right starting point. Above 2.0 mm, look at HSM-CNC30 or HSM-CNC40. For very thin disc stacks in electronics, the HSM-CNC1025 camless unit gives you better pitch control on the first piece, which matters when you are making small batches of different stack heights.

A Simple Sizing Flow You Can Use Tomorrow

• Under 1.0 mm wire, mixed batches: HSM-CNC1008 or HSM-CNC08

• 0.2 - 2.0 mm wire, long runs of one part: HSM-CNC20

• 0.8 - 3.0 mm wire, heavier compression: HSM-CNC30

• 1.8 - 4.5 mm wire, larger tension or torsion: HSM-CNC40

• 2.0 - 6.0 mm wire, heavy industrial: HSM-CNC60, choose wire rotary variant if your part needs it

• 0.1 - 1.0 mm wire, R&D or sample-heavy: HSM-CNC1008 camless

• 0.2 - 2.5 mm wire, camless flexibility: HSM-CNC1025

• 1.8 - 4.5 mm wire, complex torsion with wire rotary: HSM-CNC1045

One Open Question For You

If you are running both a belleville spring line and a tension spring line on the same floor, would you rather standardize on one CNC spring former platform and accept some flexibility loss, or run two platforms and keep each line optimized? I have seen both setups work, and the answer usually depends on how often your part mix changes. Drop your logic in the comments, I will read every one.

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Snippet: Dongzheng's HSM-CNC20 holds ±0.01 mm and lifted one Vietnam plant's daily output by 35% in 8 months, across 100+ units shipped worldwide.