DOM tube vs solid bar
DOM (drawn over mandrel) tubing is common in aftermarket linkage. In its "myth of the tube" article, MotorTrend explains that at the same outside diameter and material, solid bar is stronger than tube. A larger tube can be stiffer than a smaller solid bar and still weigh less. Wall thickness decides how well a tube resists dents from rocks.
| Question | Solid bar | Tube (DOM) |
|---|---|---|
| Same diameter, same steel | Stronger | Weaker |
| Stiffness per pound | Lower | Higher at larger diameter |
| Dent resistance | Not a concern | Depends on wall thickness |
| Ends | Often drilled and tapped | Usually welded threaded bungs |
MotorTrend's custom tie rod build also covers chromoly tube and welded bungs. Weld quality is part of strength.
Forged vs cast
The Forging Industry Association and Columbus McKinnon both describe forgings as having refined grain flow and better fatigue and impact resistance than castings of similar parts. Casting suits complex shapes. An SAE study comparing steering knuckles found forged steel had better fatigue performance than the cast iron and cast aluminum versions tested.
| Forged | Cast | |
|---|---|---|
| Grain structure | Follows the part shape | Not directional |
| Fatigue and impact (per sources) | Generally better | Generally lower |
| Complex shapes | Harder | Easier |
Questions
Is DOM stronger than solid?
Not at the same diameter and steel. Solid is stronger. A larger-diameter DOM tube can be stiffer and lighter, so compare whole parts, not labels.
Where this comes from
- MotorTrend (4-Wheel & Off-Road): Steel tubing, myth of the tube
- MotorTrend: Building a custom tie rod and drag link
- Forging Industry Association: How forgings compare to other processes
- Columbus McKinnon: Forging vs casting
- SAE paper 2004-01-0628: Fatigue life comparisons of steering knuckles (forged steel, cast iron, cast aluminum)
Last reviewed 2026-10-19. General information only: your vehicle and part maker's instructions come first.