A plastic-faced hammer is the right tool for the moments when you need real persuasion energy without marring a finished surface. Lighter than the dead-blow and with replaceable polyurethane tips on both sides, the 820A is the workshop standard for jobs where a rubber mallet's energy delivery feels insufficient but a steel hammer would leave a witness mark. The business end is a pair of 40 mm polyurethane tips on a cast-iron head; the 320 mm lacquered wooden handle gives controlled swing length without being unwieldy. What it does well The polyurethane tip is the bike-shop-safe striking face. It delivers real energy; enough to seat a headset cup, persuade a stuck quick-release, or break loose a press-fit bearing; without marring the finished component. The 40 mm tip diameter spreads the strike across a wide contact patch, which protects the workpiece from concentrated stress. The cast-iron head behind the polyurethane tips holds the weight. The hammer feels heavy in the hand for its size, because the cast-iron mass is doing the work; the polyurethane tip is the buffer between that mass and your workpiece. The two-tip design extends tool life. When one tip wears, flip the hammer and use the other. Both tips are replaceable, so the hammer can outlast the original wear cycle. Where it earns its space in the bike shop Seating press-fit bearings after the press is removed. Tapping headset cups that don't quite want to drop in. Persuading a stuck quick-release through a tight dropout. Striking the back of a chisel or punch when the workpiece is alloy or finished surface. General bike-shop persuasion where the dead-blow's weight is more than needed. When the dead-blow is the better tool For maximum energy delivery and zero rebound, the dead-blow hammer is the heavier, dedicated tool. The 820A is the lighter alternative; faster to swing, more controlled on small components. Most shops own both: the dead-blow for serious seating, the 820A for routine work. Specs Tip diameter: 40 mm (each side) Tip material: polyurethane (replaceable) Handle length: 320 mm, lacquered wood Head: cast iron Use: precision strikes against finished bike components Made in Slovenia, since 1919 Unior has been forging hand tools in Zreče since 1919, and sponsors professional road and mountain-bike race teams. The cast-iron head with replaceable polyurethane tips is the European workshop pattern; same hammer you'd find on a bench in Munich or Milan. The replaceable-tip design reflects a workshop economy where tools are repaired rather than replaced. Worn tip? New tip. The hammer body keeps going. Pro tip from our mechanics A plastic-faced hammer is the right tool for headset-spacer work. Tap the spacer to compress the steerer-tube stack before final torque on the stem; the polyurethane face won't mar the spacer finish. For the framework on which hammer fits which job: Hammers and striking tools in the bike shop →.
