Gas Springs and Shock Absorbers

Operations on a gas spring cylinder

The cylinder of a gas spring (tailgate strut, hood strut, chair gas lift, hydraulic damper) or shock absorber is a precision steel tube worked at both ends: one end closed or closed with a hole for a fitting, the bore grooved for speed and damping control, the other end pressed with guide and seals then rolled over, and sometimes an end screw locked on. TONG DA has a machine for each step.

TD-31040 gas spring cylinder closing machine
TD-31040 gas spring cylinder closing machine		TD-627 servo inner grooving machine
TD-627 servo inner grooving machine		TD-42815 gas spring roll grooving machine
TD-42815 gas spring roll grooving machine

The TONG DA cylinder line

OperationMachineNote
Cylinder end closingTD-31040 hydraulic 3-stationCold roll-spun one-piece closed end or center hole, no welding
Inner groovingTD-627 servo / TD-61530Longitudinal oil grooves on the bore for damping and speed
External groovingTD-42815 hydraulic rollingOD grooves and beads
Component pressing and edge foldingTD-AT155Press in guide and seals, roll the mouth over
Lock nutTD-91528Pneumatic end-screw tightening, single or two-station
Edge folding and punchingTD-738Tube end folding and punching

Buy one machine to fill a gap in an existing line, or plan the whole line with TONG DA.

Why gas spring makers choose TONG DA

  • Closing, grooving and assembly machines from one supplier, already matched to each other
  • TONG DA also runs contract production, so it knows what goes wrong on a cylinder line
  • Jaws, collets and hydraulic chucks supplied as spares long term
  • Building since 1989, CE certified, machines sold to the USA, Germany, Turkey, the UK, India, China and more

How to start

Send cylinder OD × wall × material × length, the closed-end and groove drawings and expected volume. TONG DA recommends models and trial-runs your tubes before you decide.

Related videos

TD-31040 Gas Spring Tube Closing – OD15/18/21 on One Machine
TD-31040 Gas Spring Tube Closing – OD15/18/21 on One Machine		Servo CNC Gas Spring Damping Groove (Inner Grooving) Machine
Servo CNC Gas Spring Damping Groove (Inner Grooving) Machine		TD-42815 Roll Grooving for Gas Spring / Tailgate Strut Tubes
TD-42815 Roll Grooving for Gas Spring / Tailgate Strut Tubes

More machine videos on our YouTube channel: youtube.com/@closingmachine

Planning a complete gas spring line?

See gas spring production line: tube cutting, damping groove, ring groove, bottom closing, oil filling, press-fit and folding, gas charging and end fittings. Spare jaws, guide tubes and chucks: spare parts.

Shock absorbers and dampers

Cylinder bottom closing, grooving, valve riveting machines and piston rod preparation: see shock absorber manufacturing machines.

TD-332 (TD-311) Automatic Tube Closing Machine | Single-Head Closing with Auto Loading & Unloading
TD-332 (TD-311) Automatic Tube Closing Machine | Single-Head Closing with Auto Loading & Unloading
TD-332 (also called TD-311) automatic tube closing machine: a single-head TD-31040 closing machine with automatic loading and unloading — tubes are fed, closed and ejected automatically, so one operator can run several machines. Tube OD Ø15–28 mm; cold spin closing, fully closed or with a hole, with no heating, welding or plug.
TD-351 (TD-31050) Two-Station Hydraulic Tube Sealing Machine | Gas Spring & Gas Lift Tube End Closing
TD-351 (TD-31050) Two-Station Hydraulic Tube Sealing Machine | Gas Spring & Gas Lift Tube End Closing
TD-351 (also called TD-31050) is a two-station (OD Ø15–50 mm) hydraulic tube sealing machine for gas lift and gas spring cylinders: it cold roll-spins the tube end closed or with a center hole, two stations in turn, one operator, no heat, weld or plug.
TD-627 Servo Inner Grooving Machine | CNC Tube Grooving for Gas Spring & Shock Absorber Cylinders
TD-627 Servo Inner Grooving Machine | CNC Tube Grooving for Gas Spring & Shock Absorber Cylinders
CNC tube grooving machine for gas spring, tailgate strut and shock absorber manufacturers. TD-627 is TONG DA’s servo inner grooving machine. It draws the longitudinal oil grooves on the bore of gas spring (tailgate strut, gas lift), shock absorber and damper cylinders that set opening speed and damping. Groove length, depth and feed are programmed on the servo slide, so a product change is a recipe recall, not a machine reset; automatic tube feeding, one operator. With the TD-31040 closing machine it forms a complete gas spring cylinder line.
TD-382 NC Closing Machine for Large Shock Absorber Cylinders and Hydraulic Cylinder Tubes
TD-382 NC Closing Machine for Large Shock Absorber Cylinders and Hydraulic Cylinder Tubes
Large shock absorber cylinders and hydraulic or pneumatic cylinder tubes need heavy-wall, pressure-tight closed ends, often with a center hole for the rod or a flat face for mounting. The TD-382 NC servo closing machine cold roll-forms large-diameter heavy-wall tube in programmed stages into a one-piece closed end; hole diameter, flat size and dome radius are program parameters set freely by the servo X/Y axes, so one machine runs different bores and different end shapes.
TD-382 NC Closing Machine for Mixed-Model Tube Shops | Many End Shapes on One Machine
TD-382 NC Closing Machine for Mixed-Model Tube Shops | Many End Shapes on One Machine
Tube shops and contract processors face a different closed-end shape on every order: another radius, another flat, a hole or no hole. A hydraulic closing machine can adjust the dome radius too and is best for fixed parts in high volume; when shapes keep changing, an NC servo machine is easier. The TD-382 NC servo closing machine keeps the end shape in a program: recall a program to change customer, change the jaw set and guide tube only when the OD changes, and take on many more parts with one machine.
TD-724 Four-Station Gas Spring Press-Fit & Edge Folding Machine
TD-724 Four-Station Gas Spring Press-Fit & Edge Folding Machine
TD-724 is a four-station rotary gas spring press-fit and edge folding machine, the same machine type as TD-AT155: the operator loads and unloads at station 1, station 2 press-fits the components pneumatically, station 3 folds the tube end closed hydraulically, and the part returns to station 1. PLC touch control; cylinder OD Ø15/18/22/24.8/28 mm, length 150–500 mm.
TD-YL506 Gas Spring Oil Filling Machine | Automatic Feeding and Precision Dispensing
TD-YL506 Gas Spring Oil Filling Machine | Automatic Feeding and Precision Dispensing
TD-YL506 is an automatic-feeding oil filling machine for gas springs and tailgate struts. It dispenses a precise amount of oil into each cylinder before closing and gas charging. Manual/Auto switch, with adjustable rotation, travel and filling speed; it works alongside our closing and press-fit/folding machines in a gas spring line.
TD-31040 Airbag Tube Closing Machine | Inflator Housing Tube End Closing
TD-31040 Airbag Tube Closing Machine | Inflator Housing Tube End Closing
TD-31040 closes the tube ends of automotive airbag components such as inflator housings and gas storage tubes. The tube end is spin-formed cold into a one-piece closed end, with no weld and no plug, and the wall thickens naturally at the closure. Range Ø10–40 mm, wall 0.8–2.0 mm; other sizes evaluated by sample.
TD-31050 Stabilizer Bar & Torsion Bar Tube Closing Machine | Hollow Tube End Spin Closing
TD-31050 Stabilizer Bar & Torsion Bar Tube Closing Machine | Hollow Tube End Spin Closing
TD-31050 hydraulic dome-type closing machine for hollow stabilizer bars, torsion bars and torsion beam tubes. Tube OD Ø15–50 mm; the tube end is cold spin-closed in one piece, with no heating, welding or plug, and no weld seam at the closure.
Cookie Notice
This website uses cookies to provide the best browsing experience. By continuing to use this site, you agree to our Cookie Policy. Learn More
Accept