Urethane Products

Hard Hat Pop-On urethane strippers

Modern ball and head type punch retainers are made with small size blocks with various outside contours which do not have enough wall thickness between the punch hole and the outside edge of the retainer to make a platform for full contact and support of the urethane strippers. The top of regular urethane strippers overhangs the retainer block and is not reinforced to withstand the pounding damage form the cutting edges of retainers, screw holes and ball release holes during punching operations.

Porter's color coded Hard Hat Pop-On punch stripper, "co-injection" molded with a tougher and harder urethane top, protects the barrel of the stripper from this damage. A layer of special 75D durameter urethane 3/16" (5mm) thick on the top end of the Pop-On punch stripper presents a much tougher surface against cutting edges. This "Hard Hat" top protects the stripper barrel and shields it from cuts and tears extending the wear life of the closed end stripper.

Hard Hat benefits include:

• Co-molded, dual hardness, one piece construction, urethane allows fast and secure mounting to any type of punch.
• The "Hard Hat'" provides higher deflection pressure for full stripping pressure around the hole , whether perforating round or shaped holes.
• Resists cuts and tears caused by steel retainer edges, bolt and dowel holes, and other contours, increasing life of the stripper.
• Provide strong, dependable stripping action without the problems of cumbersome, expensive metal strippers.
• Designed with a built in "preload" ensuring material being pertorated is under positive holding pressure prior to contact with the punch face. This "preload" along with the closed end feature ensure full contact material stripping from the punch sides and face by compensating for the permanent reduction (shrinkage) in over-all length of the stripper. This is especially important when working with thin material.
• Lowers operating cost of strippers.
• Less assembly time required. "Press on" mounting fits all manufacturers' stock retainers. No tapped mounting holes, no special holders, no special backing washers needed. No metal parts falling into your die.
• Dampens punch vibration by gripping around the punch point. (Vibration decreases punch life.)
• Oils, greases, water and ozone do not affect Porter Hard Hat "Pop-On" Urethane Strippers.
• Mar resistant hold down pressure, important when perforating precoated materials.
• Color coded for ease of identification between inch and metric, heavy duty and light duty.
• Designed with extra heavy press fit on the punch shank to further resist dropping into die when in use.

The "co-injection" molding of two different durameter urethanes into one homogeneous piece is possible only through a carefully controlled, specially developed process and is another innovation form Porter Precision Products Company to extend wear life on piercing tools.

Readily available from inventory in both inch and metric sizes.

Pop-On urethane punch strippers

Porter also offers a full line of conventional open and closed end strippers that provide:

• Resistance to oils and solvents
• 95A durometer.
• Greater pressures than equal sized die springs.
• Ease of installation.
• Dampening of vibration.
• Pop-On’s closed end gives more positive stripping and full stripping around periphery of punch point.
• Pop-On's open end are more economical.