Tapping Operation | Formula , Types , Tapping Process
Tapping Operation :
Tapping is the operation of cutting internal threads in a hole using a cutting tool called Tap. A tap has cutting edges in the shape of threads. When the tap is screwed into a hole it removes metal and cuts internal threads for tapping the hole
drilled will be smaller than the tap size.
Tap drill size = 0.8 * Outer diameter of the threads
For Example For M8 Size tap ,Drill Size should be = 0.8*8 = 6.8 mm Diameter
To understand the application and importance of the involvement of semi automation in conventional drilling machine in manufacturing.
Read more : Drilling machine | Interview Question and Answers
Types Of Tapping Process
Tapping may be done by:
– lathe machine
– milling machine
– tapping machine
HAND TAPPING PROCEDURE
1 Select drill size from chart.
When choosing a tap size, this chart is the first place to look.
Tapping Drill Size Calculation
2. If necessary, add chamfer to the hole before tapping. Chamfers and countersinks are additional features that are sometimes desired for screws. For best results, the speed of the spindle should be between 150 and 250 rpm.
3. Get a tap guide. The hole is now ready to tap. To do this, use the taps and guide blocks near the manual mills. The guide blocks will have several holes for different sized taps. Select the one closest to the size of the tap being used and place it over the drilled hole.
4. Tap the block. Peck tap using the tap wrenches. Apply gentle pressure while turning the wrench a complete turn in, then a half-turn out. Peck tap to the desired depth.
5. Complete the tap. If the tap does not go any further or the desired depth has been reached, release pressure on the tap; it has likely bottomed out. Remove the tap from the hole.
TAPPING PROCEDURE FOR LATHE
1. Mount the workpiece in the chuck.
2. Face and center drill.
3. Select the proper tap drill for the tap to be used.
4. Example: ¼ – 20 unc used # 7 drill.
5. Set the lathe to the proper speed and drill with the tap to the required depth. Use plenty cutting fluid.
6. Note: the workpiece will rotate when tapping using the lathe power. Use a very slow spindle speed. (40 to 60 rpm) and plenty of cutting fluid.
7. Chamfer the edge of the hole.
Read more : Basic and related Drilling machine Operations
More Resources /articles
Machine Tool Articles , notes , Interview Que & Ans
Manufacturing Technology Notes , Articles
Mechanical Subjectwise Basic Concept Notes ,Articles
Drilling Machine Projects
New Mechanical Projects 2020 ( All Projects Post Index List )
Mechanical engineering is one of the most physically demanding professions that involve designing, manufacturing, and maintaining mechanical systems. A mechanical engineer's work involves utilizing...
Management is an essential component of every project and team. A competent manager is indispensable in guiding the team, owning outcomes, and mediating conflicts. Engineering managers, in...