Chair legs, stroller frames and lounger armrests have traditionally been finished with a plastic end plug or a welded cap. Plugs fall out, can scratch skin and look cheap; welded caps add an operation and need grinding before plating or powder coating. TD-31040 roll-spins the tube end into a one-piece dome in a single operation, with a smooth surface that needs no preparation before finishing.
| Item | Spec |
|---|---|
| Tube OD | Ø10–40 mm |
| Wall thickness | 0.8–2.0 mm |
| Materials | Steel (ERW or cold-drawn), aluminum, stainless steel |
| Closed-end type | Dome end with adjustable radius; center hole available for glides or casters |
| Tube shape | Round tube; square tube has been closed, send a drawing for evaluation |
| Material | Size | Product |
|---|---|---|
| Aluminum | Ø31.5 × 3.2 mm | Furniture / outdoor chair tubing |
| Steel | Ø15, Ø18, Ø21 mm | Chair legs, frame tubing |
| Square tube | — | Furniture square-tube end |
Can the closed end go straight to plating or powder coating?
Yes. The dome surface is smooth and needs no grinding.
ERW tube?
Yes, provided the weld seam is sound; a weak seam will split at the closure.
Will thin aluminum wrinkle?
Not within the wall range above; aluminum’s ductility makes it one of the easiest materials. Outside the range, send samples first.
Buy a machine or subcontract to TONG DA?
TONG DA is both the machine builder and a contract tube processor. High-volume, fixed-design customers usually buy; mixed-lot or new-product customers often subcontract first and buy once the market is proven.
*Sealing machine to process tube hardness have to less HRB55 and need enough ductility.
*Because it is a cold forming process, the tolerance will be unstable due to the factors of the pipe, and the tolerance of the incoming material will affect the overall tolerance. The tolerance of the incoming material must be as small as possible.
*Sealing machine to process tube weld bead have to firm, when sealed weld bead will not dehiscence.
*Outside dia less than 20mm, within length 1000mm can to install tube holder keep tube don't shake (need extra purchase).
*Stainless steel tube hardness is softer the better and good ductility, tube material weld bead have to firm.
*Tube outside dia and thickness have to collocation each other. Especially outside dia more than 25mm tube.
| 管徑大小 OD sizeψ(mm) | 3041B.3043B | |
| 最小管厚(mm) Min OD | 最大管厚(mm) Max OD | |
10~15 | 0.8 | 2.0 |
15~20 | 0.9 | 2.0 |
20~25 | 1.0 | 2.0 |
25~32 | 1.2 | 2.0 |
32~38 | 1.5 | 2.0 |
38~40 | 1.7 | 2.0 |
| Three Station-Tube Sealing Machine | Specification |
|---|
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