GSG Cylindrical Plugs

All cylindrical plugs and discs are manufactured to ASME/ANSI B47.1 AGD standard and ASME/ANSI B89.1.5.

Cylindrical Plug Styles


Reversible Plug Gages – Can be reversed and used at the opposite end when one end becomes worn and goes out of tolerance. The gaging members are simple pins that can be removed from the handle by loosening the collet nuts at the ends. Each end of the handle is color coded (green for GO and red for NOGO). Depth steps are available upon request. Reversible plug gages are available in steel, carbide and chrome. Extra-long members also available. Gaging surfaces are hardened to Rc 58-62.

Taperlock Plug Gages – Named because of the tapered shank, which locks into the tapered hole in the end of the handle. Used for gages up to 1.5 inches. As a further aid in identification, the GO and NOGO members have different lengths in gaging surface. It’s permissible to make the NOGO gage shorter because it is not supposed to enter the part. Depth stops are available upon request. Taperlock plug gages are available in steel, carbide and chrome. Gaging surfaces are hardened to Rc 58-62.

Trilock Plug Gages – The trilock design has been found best suited for gages between 1.5 and 8 inches in diameter. The handle has three prongs on the ends, which fit into three grooves equally spaced around the central hole of the gage members. A bolt holds the member to the handle and the Trilock grooves and prongs stabilize the member. Like the pin type, Trilocks are reversible since either face can be locked to the handle. Trilock plug gages are available in steel, carbide and chrome. Gaging surfaces are hardened to Rc 58-62.

Progressive Plug Gages – In some special cases, a little gaging time can be saved by putting the GO and NOGO diameters on a single gage member. A progressive plug is suitable for checking a short hole, which is open at both ends. The hole cannot be deeper than the GO section of the plug.

Master Setting Discs – Master Setting Discs are used for setting comparators, snap gages and other precision gages. They are furnished with insulated grips to prevent heat distortion. Holders for benchtop working are also available. Discs above 2.510″/63.75 mm are black oxide on all non-gaging surfaces. Discs above 2.510″/63.75 mm are Trilock design. Master setting discs are available in steel, carbide and chrome.