The PBM 2500 machine is light weight, just 16 lbs.and is designed to bevel boiler tubes. The tool bits are held in by our wedge lock system.The torque accepting mandrel with lock in blades (no springs) easily stops any pieces from dropping down into the boiler tube. Our gear drive unit has spiral bevel gears for better torque (more teeth engagement, compared to standard straight gears that our competitors use). PERFORMANCE: Lock in mandrel blades (no springs to lose) Adjustable keyway on machinemandrel(eliminates backlashchatter) .75 hp pneumatic motor 16 lbs. approximate working weight Hardened mandrel 55 Rc.(less chance of gouging with metal chips) Tool bits are held in by our wedge lock system (keeps the tool bit locked in the cutter head to ensure chatter free bevels) Single mandrel with mandrel blades to cover size ranges Air Power requirements: 55 cfm at 90 psi. For PBM-2500 accessories, please visit our websitecontact our sales department for further assistance.