Turns A Straight Hole Into A Tapered Hole Into Which Standard Taper Pins Will Fit. The Straight-Flute And Spiral-Flute Reamers Are Generally Used By Hand While The Helical-Flute Is Designed For Machine Use. The Square On The Shanks Of The Straight And Spiral Fluted Are Suitable For Holding In A Tap Wrench Or Vise. The Straight Flute Taper Pin Reamer Is Recommended For Most Materials. The Spiral Flute Taper Pin Reamer Is Recommended For Applications Where The Reamer Tends To Wedge Itself. . The Helical-Flute Taper Pin Reamer Has The Geometry For Reaming Holes For Tapered Pins With A Machine. The Free Cutting Action At High Speeds Produces A Good Finish And Minimizes Chip Packing In The Flutes