McGuire Glossary of Fastener Terminology

M - 9 terms

MANDREL - The treaded member of the installation tool that engages the threads of the insert and applies the installation load. Spin-spin tools typically use a standard socket head cap screw as the mandrel. Most spin-pull tools use a more comlex mandrel, but some newer tools use a standard socket head cap screw. To install an insert with external threads, the mandrel has internal threads.

MAX GRIP - Maximum panel thickness into which a given blind threaded insert can be properly installed. If the panel is thicker than this value there will not be enough free counterbore to form an adequate bulb. It is common practice in the blind threaded insert industry to embed the maximum grip into the end of the part.

MAXIMUM MATERIAL CONDITION - A size condition in which the product contains the maximum amount of material permitted by the specified tolerance. For an internal thread the maximum material condition occurs when all diameters are at the minimum values. For external thread the maximum material condition occurs when all diameters are at their maximum values and root radius is at its minimum value.

MAXIMUM NUT TIGHTENING TORQUE - The maximum amount of torque that can be applied to a nut without causing a failure.

MAXIMUM SCREW TIGHTENING TORQUE - The maximum amount of torque that can be applied to a screw without causing a failure.

MINIMUM GRIP - Minimum panel thickness into which a given blind hreaded insertcan be properly installed. If the panel is thinner than this value there will too much free counterbore and the bulb will form in an uncontrolled manor.

MINIMUM MATERIAL CONDITION - A condition in which the product contains the minimum amount of material allowed by the specified tolerance. For an internal thread the mimimum material condition occurs when all diameters are at their maximum. For an external thread the mimimum material condition occurs when all diameters are at their minimum and the root radus is at a maximum.

MINIMUM SHEET THICKNESS - The thinnest section of a panel, usually measured in thousands of an inch or millimeters, into which a fastener may properly be installed. The same fastener may be installed in panels having any thinckness greater than mimimum.

MOST RECENT - Version of a standard containing current content