Sheet Metal Bend Allowance Calculator
Calculate bend allowance, bend deduction, outside setback, and flat pattern length for sheet metal bending.
Bend Allowance = (ฯ รท 180) ร Bend Angle ร (Inside Radius + K-Factor ร Material Thickness)
Bend Deduction = 2 ร Outside Setback โ Bend Allowance
Flat Pattern Length = Flange A + Flange B โ Bend Deduction
Bossing Mallet Set vs. Glazing Hammer: The Complete Guide to Essential Metal & Glass Shaping Tools
Whether you’re shaping sheet metal for auto body work or leading stained glass panels, having the right hand tool makes all the difference in both speed and finish quality. In this guide, we break down two industry-trusted tools: the MetalAce Bossing Mallet Set (3-Piece) and the Professional Glazing Hammer (#15780).
Bossing Mallet and Glazing Hammer Overview
A Bossing Mallet and a glazing hammer can both be useful workshop hand tools, but they are built for different jobs. A bossing mallet helps shape sheet metal into curves and contours. A glazing hammer helps fit delicate glass, lead came, horseshoe nails, and metal caming.
Choosing the wrong tool can leave marks in metal, make shaping harder, or increase the risk of damaging a glass panel. The sections below explain when to use each tool.
Professional Glazing Hammer (#15780) โ Built for Stained Glass and Lead Work
A double-sided tool for lead came, glass positioning, and metal caming work.
The glazing hammer is a double-sided tool designed specifically for stained glass leading and metal caming work, making it an essential piece in any glass artist’s toolkit.
Unlike a Bossing Mallet, this hammer is not designed for stretching sheet metal. It is made for controlled tapping around delicate glass pieces, lead came, horseshoe nails, and similar stained glass materials.
Key Features
- Double-sided design: A hard plastic end on one side and a rubber end on the other.
- Professional size: Approximately 10-3/4 inches in length with a head diameter of around 3 inches.
- Lightweight control: Around 10 oz, light enough for precise tapping and careful glass work.
- Two useful striking surfaces: One end for hard materials and one softer end for delicate glass placement.
What Each End Does
Hard Plastic End
Use the hard plastic end for tapping lead came, horseshoe nails, and metal caming into place.
Rubber End
Use the rubber end for gently tapping glass pieces into position without cracking or damaging them.
Who It’s For
If your projects are smaller or you prefer a lighter tool, a compact version (#15781) is also available. It offers a slightly reduced size and weight, which may be more comfortable for smaller stained glass projects and detailed work.
Glass safety tip: Use the rubber end when tapping glass into position. Always wear eye protection when cutting, handling, or fitting glass.
Bossing Mallet vs. Glazing Hammer โ Which Tool for Which Job?
Compare both tools before choosing one for metal shaping or stained glass work.
| Feature | Bossing Mallet Set | Glazing Hammer |
|---|---|---|
| Primary Use | Metal sheet shaping | Stained glass and lead work |
| Material | Polyethylene head and hardwood handle | Plastic and rubber double-ended head |
| Set Size | Three mallets with six total radii | Single double-sided tool |
| Best For | Auto body work and metal fabrication | Glass art and window restoration |
| Main Surface | Aluminum and steel panels | Glass, lead came, metal caming, and nails |
| Ideal Support Tool | Shot bag or sand bag | Stained glass workbench and horseshoe nails |
| Use Directly on Glass? | No | Yes, with the rubber end and gentle tapping |
Final Thoughts
Whether you’re a metal shaping professional or a stained glass hobbyist, choosing the right mallet or hammer directly affects the quality of your finished work.
The Bossing Mallet Set gives you the versatility to shape a range of curves in metal panels. The Professional Glazing Hammer offers the precision and control needed for delicate stained glass work.
Both tools are trusted, industry-standard picks in their respective fields. Use the Bossing Mallet for sheet-metal shaping and the glazing hammer for glass, lead came, and careful fitting work.
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Explore more helpful calculators and planning tools on AksaOrbit.
Helpful Tool Resources
Learn more about specialist metal shaping and stained glass tools.
For more information about bossing mallets, shot bags, and metal shaping hand tools, visit MetalAce hand tools . For help with stained glass leading, lead came, and glazing hammer use, explore the Delphi Glass stained glass knowledge base .

