Gas Spring Production Line | Tailgate Strut & Gas Strut Machines from Cylinder Tube to Finished Spring

One supplier for the whole gas spring cylinder line

A gas spring (gas strut, tailgate strut, lift support) goes through the same steps in every factory: the cylinder tube is cut, grooved, closed, filled, assembled and fitted with end fittings. TONG DA builds the machines for these steps and can plan them as one line. You can buy a single station to remove a bottleneck, or several stations that work together from tube to finished spring.

We have built tube machines in Tainan, Taiwan since 1989 and also run tube OEM production on our own machines, so every station is proven in real production. Our machines are working at gas spring makers in Korea, the USA, Germany, Turkey, the UK, India and mainland China.

Typical line: station by station

The order below is the usual one; it changes with your spring design (for example, springs without a damping groove skip step 2).

	1. Cut the cylinder tube to length TD-41860 hydraulic tube cutting & roll grooving machine: roll cutting without chips, so no swarf is left inside the cylinder.
	2. Damping groove (for groove-damped springs) A long axial groove is pressed inside the cylinder. It is the oil/gas bypass that sets how fast the strut opens: fast, slow or fast-then-slow. TD-627 servo damping groove machine (up to 3 grooves, different depths) or TD-61530 hydraulic grooving machine.
	3. Ring groove near the open end TD-42815 hydraulic roll grooving machine rolls the circumferential groove that holds the guide and seal pack in place.
	4. Close the cylinder bottom Cold spin closing in one piece: no welding, no plug, no heat. TD-31040 for OD 10–40 mm (one, two or three stations), TD-351 / TD-31050 for OD 15–50 mm, TD-382 NC servo closing machine when the dome, flat bottom or hole must be programmable, and TD-332 with automatic loading and unloading. Each station is independent: run three stations on the same size for volume, or on three different sizes for mixed production.
	5. Oil filling TD-YL506 gas spring oil filling machine doses the oil into the cylinder.
	6. Press-fit components and fold the tube edge TD-AT155 and TD-724 four-station machine press the guide and seal into the cylinder and fold the open end. TD-738 handles tube edge folding and punching.
	7. Gas charging The nitrogen charging station is planned together with the line, so the hand-over between assembly and charging is matched.
	8. End fittings TD-91528 two-station lock nut machine tightens the end fittings and sets their angle; single-station version.

Piston rod preparation (rod cutting, induction hardening, turning, welding) can be added through partner machines; ask us when you send your drawings.

How we plan a line with you

1. Send the cylinder and rod drawings (OD × wall × length, material, closed-end shape, groove drawing).
2. We propose which stations you need: one machine, or the full line from tube to finished spring.
3. We run samples on your own tubes and send photos and video.
4. Every machine is run with your tubes before shipment; spare parts and tooling for each tube size are supplied with it.

Videos of each station

Tube cutting – TD-41860	Damping groove – TD-627 servo	Ring groove rolling – TD-42815
Cylinder bottom closing – TD-31040	Oil filling – TD-YL506	Press-fit & edge folding – TD-AT155
Gas spring gas charging	End fitting locking – TD-91528	Piston rod lathe

More videos: youtube.com/@closingmachine · facebook.com/closingmachine

FAQ

Can we buy only some stations?
Yes. Most customers start with the closing machine or the grooving machine and add stations later; every machine also works on its own.

What changes when the cylinder size changes?
On the closing machine you change the secondary jaws and guide tube; on the grooving machine each cylinder ID has its own grooving tool set. Groove length and depth are set on the screen.

Do you make the springs for us?
We supply machines. For tube processing in Taiwan, see our contract tube processing page.

How do we start?
Send your drawings and expected sizes to sales@tdco.com.tw.

Names used in different markets

English: gas spring production line, gas strut manufacturing machines, tailgate strut assembly line, lift support machines. Turkish: gazlı amortisör üretim hattı, gazlı piston üretim makineleri. Portuguese (Brazil): linha de produção de mola a gás, máquinas para amortecedor de porta-malas. Spanish: línea de producción de resortes a gas, pistones a gas. Chinese: 气弹簧生产线、气弹簧设备、尾门撑杆生产线、氣壓棒設備。

Further reading

• Why do gas spring cylinders need inner grooving?
• Multi-station closing machine setups
• Cold vs hot spin closing