ASVAB Shop Information Practice Test 758431

Questions 5
Topics Micrometers, Pliers, Ratchets, Screwdrivers, Wrenches

Study Guide

Micrometers

Micrometers provide accuracy to the thousandths of an inch and come in outside and inside varieties. An outside micrometer is used to measure outside thickness, such as the diameter of a bolt, while an inside micrometer is used to measure the inside dimension of an object, such as the diameter of the hole of a nut or the width of a channel.

Pliers

Pliers are designed to provide a mechanical advantage, allowing the force of the hand's grip to be amplified and focused with precision. Pliers also allow finer control over objects that are too small to be manipulated by the fingers alone. The standard configuration is combination pliers which provide a fixed maximum jaw width. Other styles include adjustable joint pliers that allow selecting jaw width, needle nose pliers for holding small objects in tight spaces and locking pliers that will lock in place to hold or clamp objects together.

Ratchets

A ratchet (or socket wrench) is a wrench that applies torque in only one direction with a handle that can be moved back and forth without losing contact with the fastener. A ratchet uses variable attachments called sockets which come in a variety of drive sizes based on the size of the opening that attaches to the ratchet. Sockets with the same drive size will vary in the shape (six-point, twelve-point) and size of the nut opening that attaches to the fastener being tightened or loosened. Smaller point sized sockets are stronger and can apply greater torque while larger point sizes allow easier alignment.

Screwdrivers

Screwdrivers come in many different handle, shaft, and tip configurations for use in a wide variety of applications. Screwdrivers are classified by their tip which is shaped to fit a corresponding screw head. Common tips are slotted (flat) and Phillips (x-shaped).

Wrenches

Wrenches are used to provide grip and mechanical advantage by applying torque to turn objects (or to keep them from turning). The longer the wrench, the more torque that can be applied. Wrench ends are available in two primary types, open-end and box-end. A box-end wrench encloses the bolt head and is useful when more torque is needed or to maintain contact in difficult to reach locations. An open-end wrench is designed for speedily loosening easier to reach fasteners. Wrenches that feature one open and one box end are called combination wrenches and adjustable wrenches feature an open end with an adjustable width.