Usage Tips:2Pcs Straight Flute Tap High Speed Steel Metric Hand Flute Tap Standard Screw Tapping ToolM20x1.5 Item Type: Straight Flute Tap Material: High Speed Steel System: Metric Thread Quantity: 4 Thread Tolerance Grade: 0.014 Through Hole/blind Hole: Through Hole Tap Style: Straight Slot Thread Codes: Fin Thread Application: Suitable for Thick Steel, Rubber, Aluminum, Copper, and WoodUsage: a Set of Products Consists of 2 Pieces, Which Can Also Be Divided into Head Cone and Two Cones. Function of Tap: There is a Section of Taper at the Front of the Tap, Which is Glossy Without Screw Thread (very Shallow), So As to Facilitate the "alignment" Between the Tap and the Tapping Hole and Ensure the Perpendicularity of the Tap and the Hole for Glossy Tapping. Function of the Second Cone: in Addition to Machining the Allowance of the Head Cone to Meet the Standard, It Also Plays the Role of Polishing the Screw Thread (deburring). for the Screw Thread with "blind Hole", It Can Be "tapped to the Bottom. Simply, It Can Be Said That the Head Cone is Rough Machining and the Second Cone is Fine Machining. The Workpiece to Be Machined Shall Be Clamped Correctly. Generally, the Side of the Workpiece That Needs to Be Tapped Shall Be Placed in a Horizontal or Vertical Position. in This Way, when Tapping, It is Easier to Judge and Maintain the Direction of the Tap Perpendicular to the Workpiece Thread Base. when Starting Tapping, Place the Tap As Far As Possible, then Press the Axes Direction of the Tap with One Hand and Gently Rotate the Hinge with the Other Hand Screw. when the Tap Rotates for 1 - 2 Turns, Observe Whether the Tap is Perpendicular to the Thread Base Face of the Workpiece from the Front or Side. if Necessary, Use aright angle ruler to Correct It. Generally, the Direction of the Tap is Basically Determined After Tapping 3 - 4 Turns of Threads. if the Tapping is Not Correct, Screw out the Tap, Correct It with Two Taps, and then Tap the Thread with a Head Tap. when All the Cutting Parts of the Tap Are Inserted when Entering the Workpiece, It is No Longer Necessary to Apply Axial Force, and It Can Be Screwed in Naturally by the Thread.