Drilling Guides

Switch Grip® Drilling & Installation Guide

Switch Grip® Interchangeable Thumb Inserts have revolutionized the way bowlers and pro shops use bowling balls. Bowlers now enjoy the same feel in every ball and can quickly adjust to fluctuations in thumb size without the hassles of using bowling tape. Bowling balls equipped with Switch Grip® can be shared among friends with similar insert sizes/span. Many retailers using Switch Grip™ also feature Try Before You Buy services allowing bowlers to sample different bowling balls before they purchase. Switch Grip® is used by bowlers of all skill levels and has quickly become the most accepted and widely used interchangeable thumb insert on the market.

Switch Grip® is designed to withstand over 180 lbs. of dead weight or grip pressure before possible failure. Equally important to the quality and durability of the product is proper installation. To ensure the best results, pro shops must be sure to review drilling and installation instructions before installing.

 Vacuum Grip Drill Technique


NOTE: Please read instructions fully before drilling.
For Tech Support call: 1-800-530-9878 or Int’l: 586-598-3948.

  1. Use 1 1/32″ drill bit. Hole should be 1/16″ larger than the recommended insert o.d.
  2. Drill hole 1″ deep.
  3. Replace 1 1/32″ drill bit with 31/32″ or recommended insert outside diameter (for stronger vacuum use smaller drill bit i.e. 61/64 for standard outside diameter insert)
  4. Drill hole the full depth of insert (Turbo multi-function inserts 1 3/4″)
  5. You have now created a multi-tier at the bottom of the hole.
  6. Install finger insert. Glue bottom of grip into smaller hole. When creating a vacuum grip you must use at least 2 sizes smaller than standard fingertip size. Grip will expand to fit inside hole diameter.
  7. Apply adhesive (Turbo Zip Plus-45 recommended) to the front of hole, between finger insert and bowling ball. ONLY apply glue to the front wall.

Download a printable version of the Vacuum Grip Drill Technique (pdf)