Cam vs Camless Spring Machine: Which Fits 0.2-4.5mm Wire?

Running a spring shop for over two decades, the question I get most often is still the simplest one: should I buy a cam machine or a camless one? The honest answer is it depends on your wire diameter, your batch sizes, and how often you change part numbers. Let me break it down using real machine specs, so you can decide with data, not marketing fluff.

Why Wire Diameter Is the First Filter

Most buyers start with budget, but in my experience wire diameter decides more than half the decision. Here is a quick reference table covering the main CNC spring machine lineup we run at Dongzheng:

Model	Type	Wire Range	Typical Application
HSM-CNC08	Spring coiling machine	0.08-1.0 mm	Micro electronics, watch parts
HSM-CNC20	Cam spring machine	0.2-2.0 mm	General compression/torsion springs
HSM-CNC30	Spring coiling machine	0.8-3.0 mm	Auto seating, hardware
HSM-CNC40	Cam spring machine	1.8-4.5 mm	Industrial heavy springs
HSM-CNC60	Cam spring machine	2.0-6.0 mm	Garage door, large coil springs
HSM-CNC1008	Camless spring machine	0.1-1.0 mm	Pen parts, micro connectors
HSM-CNC1025	Camless spring machine	0.2-2.5 mm	Precision wire forming
HSM-CNC1045	Camless spring machine w/ wire rotatory	1.8-4.5 mm	Complex 3D shapes, large wire

Notice the split. Under 2.5 mm wire, camless machines dominate because changeover is software-driven. Above that, especially past 3 mm, cam machines still hold the ground for heavier torsion and compression springs. The HSM-CNC60 even comes in two versions, with and without wire rotary, so heavy-duty garage door spring coiling is handled by cam mechanics for sheer force tolerance.

Cam Spring Machines: Where They Earn Their Keep

A cam spring machine like the HSM-CNC20 uses mechanical cams to control the sliding, cutting, and pitch movements. Once your cam profile is ground and tuned, it repeats that motion with very little electronic lag. For a stable, long-running part, nothing beats this consistency.

Our flagship HSM-CNC20 covers 0.2 to 4.0 mm wire diameter and has over 100 units running globally. One Vietnamese customer, who has been using it since 2010, hit a 35 percent daily output increase within 8 months of installation, and the ±0.01 mm precision has stayed steady for years. Another Brazilian customer bought two HSM-CNC20 units in 2022 and has never even opened our WeChat service group, because they have not needed a single service call.

That kind of uptime is what cam machines do best. They are slightly slower to set up for new parts, because every geometry change may mean a new cam, but once running, they run.

Camless Spring Machines: Speed and Flexibility

Camless machines replace mechanical cams with servo-driven axes controlled by software. Want to change from a compression spring to a torsion spring to a complex 3D wire form? You just load a new program.

This is why camless is the natural fit for a steel wire bending machine for pen parts application, where lots of micro-bends and unique shapes come off the same line in small batches. The HSM-CNC1008 handles 0.1 to 1.0 mm wire with no cam changeover, which is exactly what medical and pen-component manufacturers need.

The HSM-CNC1025 covers 0.2 to 2.5 mm and the HSM-CNC1045 pushes camless all the way to 4.5 mm wire with a wire rotary axis for 3D forming. These are also the machines to look at when someone searches for a cnc wire forming machine for wire 6mm applications, though for true 6 mm capability you usually pair camless forming with a dedicated heavy coiling stage, and that is where the HSM-CNC60 steps in.

Side-by-Side Comparison

Criterion	Cam Spring Machine	Camless Spring Machine
Setup time per new part	30-90 minutes (mechanical)	5-15 minutes (program)
Best wire range	0.2-6.0 mm	0.1-4.5 mm
Repeatability on long runs	Excellent	Excellent
Flexibility across part numbers	Limited without cam change	Very high
Ideal batch size	Medium to large	Small to medium
Maintenance access	Mechanical, easy to inspect	Servo and electronic focus
Example model	HSM-CNC20 / HSM-CNC40	HSM-CNC1025 / HSM-CNC1045

Reading Your Own Shop Into the Specs

If your order book is 80 percent repeat parts and you run the same geometry for months, a cam machine will probably outearn a camless one. If your customers send new drawings every week, or you serve markets like medical devices, automotive seating, or pen components where part variety is the norm, camless pays for itself in saved setup labor.

A cnc spring machine small for volute spring production is a great example of the camless advantage, because volute geometry is awkward to cam and quick to program.

A Few Field Notes From Real Customers

In 2026, a Shenzhen customer added two HSM-CNC20 units plus an HSM-CNC08 coiler. Their setup technician had used many brands over the years and specifically praised the machines for being stable, durable, and easy to tune. That kind of operator-level endorsement only comes when the machine behaves predictably day after day.

In March 2026, a Vietnamese customer bought one HSM-CNC20 after seeing our machine at another factory. He had already purchased a different brand earlier, and once he watched our machine running, the stability difference was obvious enough to trigger an immediate purchase decision.

Across our export markets, we have shipped 40-plus units to Vietnam, 10-plus to Brazil, and 5-plus each to Indonesia and South Korea. We have 150-plus units in global field operation outside China, serving customers in 15-plus countries, and an annual capacity above 150 sets.

So Which One Should You Pick?

Start with the largest wire diameter on your order book. If it is above 4.5 mm, you are mostly in cam territory, and the HSM-CNC40 or HSM-CNC60 is your working range. If it is below 2.5 mm and your batches are short or varied, camless from the HSM-CNC1008 family will save you the most setup hours. The 2.5 to 4.5 mm band is the genuine overlap zone, and that is where running both a cam and a camless line is common.