4130 Tubing — 0.035" Wall
0.035" is the lightest wall in regular 4130 supply, equal to 0.89 mm or 20 gauge. It is an aircraft and bicycle wall, chosen when every gram counts and the loads are well understood.
Where a 0.035" Wall Is Used
Light aircraft fuselage and tail structures use this wall extensively in diameters from 3/8" to 1". Bicycle frame builders use it for main tubes, and race car builders for body supports, ducting frames and other non-structural members.
The wall is not suitable for roll structures or for tubes that will be knocked about in service, because thin tube dents easily and a dent removes much of its buckling strength.
Working With Thin Wall
TIG welding is the normal process at this thickness. Heat input has to be low and fit-up tight, since gaps are difficult to bridge without burning through. Bends need internal support or a generous radius. More detail is on the thin wall tubing page and in the welding guide.
0.035" Wall 4130 Tubing: OD, Bore and Weight Table
The table shows how a 0.035" (0.89 mm) wall behaves across common outside diameters. The OD-to-wall ratio is a quick guide to how easily the tube bends and how readily it dents.
| OD (in) | OD (mm) | ID (in) | OD / wall ratio | Weight (lb/ft) | Weight (kg/m) |
|---|---|---|---|---|---|
| 0.375" | 9.52 | 0.305" | 10.7 | 0.13 | 0.19 |
| 0.500" | 12.70 | 0.430" | 14.3 | 0.17 | 0.26 |
| 0.625" | 15.88 | 0.555" | 17.9 | 0.22 | 0.33 |
| 0.750" | 19.05 | 0.680" | 21.4 | 0.27 | 0.40 |
| 0.875" | 22.22 | 0.805" | 25.0 | 0.31 | 0.47 |
| 1.000" | 25.40 | 0.930" | 28.6 | 0.36 | 0.54 |
| 1.125" | 28.57 | 1.055" | 32.1 | 0.41 | 0.61 |
| 1.250" | 31.75 | 1.180" | 35.7 | 0.45 | 0.68 |
| 1.375" | 34.92 | 1.305" | 39.3 | 0.50 | 0.75 |
| 1.500" | 38.10 | 1.430" | 42.9 | 0.55 | 0.82 |
| 1.625" | 41.27 | 1.555" | 46.4 | 0.59 | 0.89 |
| 1.750" | 44.45 | 1.680" | 50.0 | 0.64 | 0.95 |
| 2.000" | 50.80 | 1.930" | 57.1 | 0.74 | 1.09 |
Values are calculated from nominal dimensions (weight = (OD − wall) × wall × 10.69). A row in this table is a dimensional reference, not a statement that the size is held in stock; confirm availability when you enquire.
Frequently Asked Questions
What is 0.035" wall in millimetres and gauge?
0.035" equals 0.89 mm and corresponds to 20 gauge (BWG).
How much does 1.000" × 0.035" 4130 tubing weigh?
About 0.36 lb/ft, or 0.54 kg/m, from nominal dimensions.
Can 0.035" wall 4130 be MIG welded?
It is not recommended. The wall is thin enough that TIG, with its finer heat control, is the practical choice.
Which diameters are common with a 0.035" wall?
Small diameters from about 0.375" to 1.000" OD, as used in aircraft and bicycle frames.
Enquire for 4130 Tubing with 0.035" Wall
Specify your required OD, condition, standard, and footage to accompany the 0.035" wall requirement.
- Wall: 0.035"
- OD required
- Standard (ASTM A519)
- Condition
- Footage
- MTC 3.1
- Delivery