3-56 Unf Flexible Hole Location Plug. Vermont Gage Usa Part # 261108500. Flexible Hole Location Plugs Are Used To Inspect The Centerline Distance Between Two Or More Threaded Holes. They May Also Be Used To Measure The Perpendicularity From The Face Of The Threaded Part To The Centerline Pitch Diameter Of The Threaded Hole. The Parallelism Between Other Features And The Centerline Pitch Diameter Of The Threaded Hole May Be Measured As Well. The Key Feature Is The Gages Are Designed To Engage The Threads On The Flanks, Not The Face Of The Part. Hole Location Plugs Are Used To Measure The Location Of A Threaded Hole In A Product, Typically With A Cmm. Vermont Gage's Flexible Hole Location Plugs Larger Than #10 (M5) Are Slotted At 90 Degree Increments, While Hole Location Plugs #10 (M5) And Smaller And Are Of Solid Construction With Front Taper Covering The Entire Product Tolerance. Both Styles Insure Positive Location On The Thread Flank Regardless Of The Size Of The Hole Within The Product Tolerance. Certificate Of Accuracy Included. Vermont Gage Usa Part #261108500