Check the listing for details. Stripped inner gear replace Boston model 18 / 19 pencil sharpener X-acto 18xxxCN. Condition: New. Listed at 8.88 USD. We've developed the repair / restore 25 tooth insert for a stripped inner gear Boston Electric Pencil Sharpener Model 18 and 19 stripped inner gear (blade assembly guide)Also will fit X-ACTO ELECTRIC PENCIL SHARPENER MODEL 18XXXCNThis fine Nylon gear has improved design for better durability and performanceOur gear is 20% thicker compare to OEM It fit rotating blade gear better than original thanks to a 20 degree bevel angle 3D printed out of Nylon - tough and flexible plasticOnly Nylons should be used for gears where a slippery surface is desired. All other materials (PLA, ABC, PET, etc.) will grind creating a plastic dust and eventually fail! Installation require some mechanical skills:a. Take unplugged sharpener apart b. Cut stripped part off to the length of ≤8mm (0.3") c. Drill two 1/16" pilot holes and attach new gear with 2 stainless steel screws (included) (shavings release opening must face down) d. Unscrew steel cutting blade shaft, clean and lubricate e. Assemble in reverse order For details, please review all pictures.Sharpener mechanism pictured for fit illustration only and is not included. We also carry 70t gear replacement for model 18 and 19, eBay item number: 362575506231 Thanks for reading.