I. Hammer Grip Posture

• Grip position: Hold the rear 1/4 of the hammer handle; never grip the middle or front section.

• Finger placement: Secure the handle firmly with the little finger and ring finger as fixed supports; rest the index and middle fingers loosely against the handle, with the thumb pressing against the side of the handle.

• Force application: Generate striking force solely by wrist rotation while keeping the forearm and upper arm stationary. Strike using the inertial swing of the wrist; avoid swinging the entire arm.

II. Two Core Hammering Techniques (Anvil/ Dolly is Mandatory)

A body hammer must be used with a dolly (anvil) and is rarely used alone on sheet metal.

1. Off-dolly Method (Preferred for dent repair, most commonly used)

• Operation: Place the dolly behind the raised area adjacent to the dent, then strike the dent surface with the hammer.

• Principle: Impact force transfers to the dolly, pressing down the raised portion and gradually lifting the dent upward.

• Application: Large shallow dents on thin sheet metal of doors or hoods; prevents excessive stretching of metal panels.

2. On-dolly Method (For high-spot flattening and fine finishing)

• Operation: Fit the dolly tightly directly behind the dent and strike the front of the dent perpendicularly with the hammer.

• Principle: Combined downward hammer pressure and upward support from the dolly pushes the dent back into original shape.

• Application: Finishing raised bumps and small bulges after preliminary dent restoration.

III. Key Hammering Operation Specifications

• Striking force: Prefer frequent light taps over heavy blows

Never strike thin body panels (0.6～0.8 mm thick) with heavy hammering; excessive impact stretches metal and creates unwanted ripples. Use continuous short light taps instead.

• Hammering sequence: Work from the outer edge of the dent toward its center

Repair the dent perimeter first and gradually move inward; never pound the deepest dent center directly.

• Strike placement: Land the full hammer face flat on the panel; avoid striking with hammer corners to prevent new indentations.

• Striking frequency: Maintain a steady pace of 1～2 strikes per second for general finishing work.

IV. Application Rules for Different Types of Body Hammers

• Pick hammer: Use the pointed end to push out small dents from inner panel gaps; use the flat end to knock down high spots. Never strike painted surfaces hard with the pointed tip.

• Shrinking hammer (textured-face hammer): After metal stretching causes bulging, tap raised bulges with the textured side to cold-shrink metal; stagger striking positions for each tap.

• Rubber/nylon mallet: Used exclusively for reshaping original painted panels; soft contact avoids paint chipping and surface dents.

• Finishing hammer: For final fine leveling with small light taps to remove minor unevenness.

V. Prohibitions & Safety Regulations

❌ Never use body hammers to strike bolts, hard iron parts or welding spots, which damages hammer faces and leaves burrs that scratch sheet metal.

❌ Never pound thin panels violently without supporting them with a dolly.

✅ Always wear safety goggles to protect eyes from flying metal debris.

✅ Immediately discontinue use if the hammer handle becomes loose or cracked to prevent the hammer head from flying off.

VI. Concise Working Mnemonic

Grip the rear end, swing with wrist sway;

Off-dolly for dents, on-dolly high spots lay;

Work outside in, tap soft not hard all day.