A cracked axle stand is a serious safety hazard — these stands support vehicles that can weigh over a tonne, and a failure can be fatal. In most cases, replacing the stand is safer and cheaper than welding it, but if you have solid welding skills and the right equipment, a repair may be possible. Read on to understand the risks, the process, and when to call a professional.
Why This Repair Demands Respect
Axle stands (also called jack stands) are safety-critical components. A weld that looks solid on the surface can hide porosity, incomplete fusion, or heat-affected zone cracking — any of which can cause sudden, catastrophic collapse. WorkSafe NZ classifies working under unsupported vehicles as a high-risk activity, and a failed repair puts you or anyone nearby in serious danger. Before you pick up a welding torch, honestly assess whether the repair is worth the risk versus simply buying a new set of stands.
Assess the Damage First
Not all cracks are equal. Consider the following before proceeding:
- Surface crack vs. through-crack: A hairline surface crack in a non-load-bearing weld bead may be repairable. A crack running through the main upright, base plate, or ratchet mechanism is a strong indicator the stand should be scrapped.
- Location of the crack: Cracks near the locking pin slot, saddle, or base legs are in the highest-stress zones and are very difficult to repair reliably.
- Cause of the crack: If the stand was overloaded or dropped, the surrounding steel may be work-hardened or deformed in ways that aren't visible.
- Steel grade: Most axle stands are made from mild steel (similar to AS/NZS 3678 Grade 250 or 350), but some cheaper imported stands use unknown alloys that can be difficult to weld without cracking further.
If you have any doubt about the crack's extent, discard the stand. A new pair of quality stands from Bunnings or Mitre 10 is a small price compared to the cost of an injury.
Tools and Equipment You'll Need
- MIG welder (a 150–200 amp unit is suitable for typical 3–6 mm stand steel) or a stick welder with appropriate rods (E6013 or E7018 are common choices for mild steel)
- Angle grinder with a flap disc and cutting disc
- Wire brush and degreaser
- Welding helmet (auto-darkening recommended), welding gloves, leather apron
- Clamps or a vice to hold the stand securely
- Dye penetrant (crack detection spray) — optional but highly recommended
Step-by-Step: Welding a Cracked Axle Stand
1. Clean the Area Thoroughly
Grind away all paint, rust, grease, and mill scale from at least 25 mm either side of the crack. Contamination is the number-one cause of weak welds. Wipe down with a degreaser and allow to dry completely.
2. Identify the Full Extent of the Crack
Use dye penetrant spray (available at most welding suppliers) to reveal the true length of the crack, including any hidden branching. Mark the ends with a marker.
3. Grind Out the Crack (Vee-Groove)
Using a cutting disc or grinding wheel, grind a V-groove along the full length of the crack to a depth of roughly two-thirds of the material thickness. This gives the weld bead room to achieve full penetration. Do not simply weld over the top of a crack — this almost always results in a weak, superficial repair.
4. Drill Stop Holes
At each end of the crack, drill a small hole (3–4 mm diameter) to prevent the crack propagating further during or after welding.
5. Weld in Passes
Using your MIG or stick welder set to an appropriate amperage for the material thickness, run a root pass along the groove. Allow to cool slightly, chip slag (if stick welding), and run a second fill/cap pass. Avoid excessive heat input, which can distort the stand or create a large heat-affected zone.
6. Inspect the Weld
Once cool, grind the weld flush and re-apply dye penetrant to check for surface porosity or new cracking. The weld should be uniform, with no visible voids or undercut.
7. Load-Test Conservatively — Then Replace Anyway
Even a visually perfect weld repair on a safety-critical item carries residual risk. Many experienced welders and safety professionals recommend using a repaired axle stand only as a secondary support (alongside a good hydraulic jack or another stand), never as the sole support under a vehicle.
Personal Protective Equipment and Workshop Safety
- Always weld in a well-ventilated area — welding fumes are hazardous. Refer to WorkSafe NZ guidance on fume extraction.
- Keep a fire extinguisher within reach and clear flammables from the work area.
- Never weld near fuel tanks, LPG cylinders, or brake fluid.
- Wear UV-rated eye protection even when others nearby are welding.
When to Call a Professional
Consider engaging a qualified tradesperson welder if:
- You are not confident in your welding technique or equipment calibration.
- The crack is in a high-stress structural zone (upright, base, or locking mechanism).
- The steel grade is unknown or the stand is of uncertain origin.
- You want a professional assessment of whether the repair is viable at all.
A professional welder can also perform non-destructive testing (such as dye penetrant or magnetic particle inspection) to give greater confidence in the repair. You can find qualified local welders on tradedirectory.co.nz.
Note: Welding is not classified as restricted building work under the MBIE Building Performance framework in the same way as electrical or plumbing work, but structural and pressure welding in commercial contexts does require certified welders under NZS/AWS standards. For a personal workshop repair like this, there is no legal licensing requirement — but competence and safety are still paramount.
The Honest Recommendation
For most homeowners, buying a new pair of rated axle stands is the safest and most cost-effective solution. Quality stands rated to 2–3 tonnes are widely available and, as a guide, cost varies depending on capacity and brand — check current pricing at your local hardware store. Your safety is worth more than the cost of a replacement.
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