Tap indices are commonly used in the measurement and inspection of threaded holes and nuts. They help to determine the correct size and pitch of the thread, as well as to ensure that the thread is properly formed. There are several types of tap indices available, each designed for a specific purpose. Here are some of the most common types of tap indices:
Pitch Diameter Tap Index:
This type of tap index is used to measure the pitch diameter of a thread. It consists of a set of wires that are placed on the thread at the pitch diameter and then measured with a micrometer. This measurement is used to calculate the pitch diameter of the thread.
Thread Angle Tap Index:
This type of tap index is used to measure the thread angle of a thread. It consists of a gauge that is placed on the thread at the crest and root of the thread. The angle is then measured with a protractor or angle gauge.
Thread Height Tap Index:
This type of tap index is used to measure the height of the thread. It consists of a gauge that is placed on the thread at the crest and root of the thread. The height is then measured with a micrometer.
Thread Depth Tap Index:
This type of tap index is used to measure the depth of the thread. It consists of a gauge that is placed on the thread at the crest and root of the thread. The depth is then measured with a micrometer.
Thread Pitch Tap Index:
This type of tap index is used to measure the pitch of the thread. It consists of a gauge that is placed on the thread at the crest and root of the thread. The pitch is then measured with a pitch gauge.
Thread Form Tap Index:
This type of tap index is used to measure the form of the thread. It consists of a gauge that is placed on the thread at the crest and root of the thread. The form is then measured with a form gauge.
Thread Runout Tap Index:
This type of tap index is used to measure the runout of the thread. It consists of a gauge that is placed on the thread at the crest and root of the thread. The runout is then measured with a dial indicator.
Thread Taper Tap Index:
This type of tap index is used to measure the taper of the thread. It consists of a gauge that is placed on the thread at the crest and root of the thread. The taper is then measured with a taper gauge.
Thread Lead Tap Index:
This type of tap index is used to measure the lead of the thread. It consists of a gauge that is placed on the thread at the crest and root of the thread. The lead is then measured with a lead gauge.
Thread Chaser Tap Index:
This type of tap index is used to measure the thread on a chaser. It consists of a gauge that is placed on the chaser at the crest and root of the thread. The thread is then measured with a pitch gauge.
In conclusion, there are many types of tap indices available, each designed for a specific purpose in the measurement and inspection of threaded holes and nuts. Choosing the right tap index for the job is important to ensure accurate and reliable results.