Difference between revisions of "Tapping"
| Line 18: | Line 18: | ||
#Mark and drill an appropriatly sized hole | #Mark and drill an appropriatly sized hole | ||
| − | #*The hole should be in an area where fittings or pipe overlap (double thickness)[[Image:ReltonRapidTap.gif|right|thumb| | + | #*The hole should be in an area where fittings or pipe overlap (double thickness)[[Image:ReltonRapidTap.gif|right|thumb|An appropriate cutting fluid for tapping holes. It is usually available at tool stores. ]] |
#*Find correct hole size with a [http://www.engineersedge.com/tap_drill_chart.htm Tap/Drill Chart] | #*Find correct hole size with a [http://www.engineersedge.com/tap_drill_chart.htm Tap/Drill Chart] | ||
#Insert the tap into the tap wrench | #Insert the tap into the tap wrench | ||
Revision as of 21:49, 18 April 2006
Tapping is the process of cutting threads on the inside diameter of a hole with a tool called a tap. It is used to thread holes for mounting:
- Pressure gauges
- Fuel meters
- Electrodes (Bolts)
- Safety valves
- Other
Types of threads
There are a few diffent thread systems that are used in spudgun construction
- NPT (National Pipe Taper)
- BSP (British Standard Pipe)
- NF (National Fine)
- NC (National Course)
The process
- Mark and drill an appropriatly sized hole
- The hole should be in an area where fittings or pipe overlap (double thickness)
- Find correct hole size with a Tap/Drill Chart
- Insert the tap into the tap wrench
- If you don't have a tap wrench, a normal crescent wrench can be used
- Cut the threads
- Be careful to keep the tap straight or you will end up with crooked threads
- When tapping plastic (or any other material) be sure to use an appropriate cutting fluid such as RapidTap®
- Apply downward pressure while slowly turning the tap clockwise 180 degrees, then back out 90 degrees counterclockwise to clear the chips
- For tapered threads, stop as soon as the entire length of the hole is threaded
