Quick answer
A ring mandrel is the essential tool for accurately sizing and shaping rings. Follow these steps to avoid common mistakes and achieve professional results.
Why use a steel ring mandrel?
Steel ring mandrels are hardened to withstand hammering without deforming, giving you a reliable reference for sizing and shaping. A rectangular mandrel, like the 13" steel model with 6 x 8 mm and 15 x 20 mm profiles, is specifically designed for square-edged rings. Its flat surfaces help maintain crisp corners, preventing the ovalisation that can happen with round mandrels.
Step-by-step guide to using a ring mandrel
- 1. Select the correct mandrel profile: Choose a mandrel that matches your ring shape. For square-edged rings, use a rectangular mandrel. For standard rounded rings, a tapered round mandrel works best. Using the wrong profile can distort the ring shape and require extra correction work.
- 2. Mark your target size: Place the ring on the mandrel and slide it until it fits snugly at the desired size. Use a fine-tip marker or scribe to mark the position on the ring shank. Always double-check the size with a ring sizer or gauge before marking.
- 3. Secure the mandrel firmly: Clamp the mandrel in a bench vice or use a mandrel stand to prevent movement. A stable setup is crucial for accurate hammering and shaping. A loose mandrel can cause the ring to shift, leading to uneven shaping.
- 4. Hammer gently to shape: Use a rawhide or nylon mallet to tap the ring around the mandrel. Work your way around the ring gradually, applying even pressure to avoid flat spots. Avoid using a steel hammer directly on the ring, as it can mark the metal.
- 5. Check and adjust size: After shaping, slide the ring off and test it on a ring sizer or the mandrel again. If it's too tight, repeat step 4 on a slightly larger mandrel section. It's easier to remove metal than to add it, so size up gradually.
- 6. Finish with a polish: Once the ring is the correct size and shape, remove any marks from the mandrel by sanding and polishing the shank. Use progressively finer grits to achieve a smooth, professional finish.
Product fact
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Rectangular Ring Mandrel, Steel Forming Tool, 13" — 6 x 8 mm & 15 x 20 mm: This steel rectangular ring mandrel provides a solid form for shaping and sizing square-edged rings, preventing unwanted distortion during hammering. Its flat surfaces guide the metal to preserve crisp corners, unlike round mandrels that encourage ovalisation.
Rectangular Ring Mandrel, Steel Forming Tool, 13" — 6 x 8 mm & 15 x 20 mm