Thread pitch gauge
Encyclopedia
Screw thread
A screw thread, often shortened to thread, is a helical structure used to convert between rotational and linear movement or force. A screw thread is a ridge wrapped around a cylinder or cone in the form of a helix, with the former being called a straight thread and the latter called a tapered thread...
. The uppermost gauge in the image is an ISO metric
ISO metric screw thread
The ISO metric screw threads are the world-wide most commonly used type of general-purpose screw thread. They were one of the first international standards agreed when the International Organization for Standardization was set up in 1947.-Basic profile:...
pitch gauge, the larger gauge in the center is for measuring the Acme thread form
Acme thread form
Trapezoidal thread forms are screw thread profiles with trapezoidal outlines. They are the most common forms used for leadscrews . They offer high strength and ease of manufacture. They are typically found where large loads or high accuracy are required, as in a vise or the leadscrew of a lathe...
, and the lower gauge is for Whitworth
British Standard Whitworth
British Standard Whitworth is one of a number of imperial unit based screw thread standards which use the same bolt heads and nut hexagonal sizes, the others being British Standard Fine thread and British Standard Cycle...
screws.
Thread pitch gauges are used as a reference tool in determining the pitch of a thread that is on a screw or in a tapped hole. This tool is not used as a precision measuring instrument. This device allows the user to determine the profile of the given thread and quickly categorize the thread by shape and pitch. This device also saves time, in that it removes the need for the user to measure and calculate the thread pitch of the threaded item.
Parts of Screw Gauge
1)U shaped metallic frame2)Hallow cylindrical tube
3)Index line
4)Milled head(H)
5)Safety device(D)
6)Head scale(Slopped Edge)
7)Pitch scale(mm)