User:Jstapko/EngLab/toolcerts/screwdriver

= Screwdrivers = Quiz (take after reading this wiki)

Warnings

 * 1) Make sure that the force you are exerting on screwdrivers is never in a direction such that if the driver slips off the screw, it will poke your hand.
 * 2) Phillips screwdrivers are available in several sizes. Using one of the wrong size on a screw can cause damage to both the screw and screwdriver.  This makes the screw much more difficult to remove and ruins the screwdriver.

Quick Start Guide

 * 1) Identify the drive type
 * 2) select the proper driver.  Drivers available in the HCC lab include:
 * slotted (several sizes)
 * torx
 * pinned torx
 * Phillips
 * square
 * 1) remove or insert the fastener, keeping in mind warning (1), above.
 * 2) take note of any washers, spacers, or springs released by removing the fastener

Overview
Screwdrivers are for inserting or removing threaded or cam locking fasteners. Some of the most commonly used types include slotted, or straight blade, screwdrivers, Phillips screwdrivers, and torx drivers. Less common types include square or Robertson drivers, triangular head, pin torx, and clutch head. This is by no means an exhaustive list; if your fastener doesn't match any described, check the links on this page for websites that can assist you in identifying your fastener.

Unacceptable Uses
It is fairly common, though poor, practice in shops to use screwdrivers for functions besides turning screws. For example, slotted, or straight blade, screwdrivers are used as prybars, scrapers, and electrical connectors. Phillips screwdrivers, because they come to a point, are sometimes used to poke holes in soft objects such as would normally be done with an awl, but an awl is not immediately available. Another common misuse of a Phillips screwdriver is to use it for countersinking holes for screw heads. However, using screwdrivers for purposes other than their original design use can damage the tool, reducing its effectiveness for its intended purpose. In the HCC lab, we have or can make the appropriate tools for other jobs, so using screwdrivers for purposes other than driving screws is unacceptable.

types of screwdriver
Screwdrivers, regardless of drive type, come in several varieties, including:
 * ratcheting
 * solid shaft
 * bit driver tool
 * right angle, or tight spaces, screwdriver
 * flexible shaft screwdriver

Screwdriver Sizes
Screwdrivers come in different sizes witin a given drive type. Slotted screws are defined by their width and thickness, while Phillips screwdrivers are numbered 0-5, larger numbers meaning larger drivers. Other drive types are sized by numbers, prefixed with a letter, as described here. It is important to use the proper size of screwdriver for your fastener because if it is too large or too small, it can slip in the head while attempting to drive. This action can strip the head, making the screw impossible to remove or reuse.

Worn/Damaged Drivers
Worn or damaged screwdrivers can cause several problems:
 * a worn/damaged driver can slip in the screw head while driving, which can strip the screw head, making it impossible to remove or use again
 * a worn/damaged driver can slip out of the screw head more easily, increasing the likelihood of poking the operator's hand, arm, stomach, etc,

To prevent this, inspect your bit or screwdriver before using. If it seems to be damaged, do not use it, and report it to a professor or lab assistant. Do not, however, throw it away yourself.

Additional Resources
http://sizes.com/tools/screw_drive.htm good reference for screw drive sizes http://www.doityourself.com/stry/an-easy-guide-to-phillips-head-screwdriver-sizes#b a brief introduction to screw sizes
 * Wikipedia: Screw Drives
 * Wikipedia: Screw
 * boltdepot's guide to fasteners
 * McMaster-Carr fasteners section
 * Wikipedia: Fasteners
 * Fastenal Fastener Technical Guide
 * NASA fastener design manual
 * Machinery's Handbook, 5th edition Bolts section starts on page 765.

this page needs:

 * possibly more content in section 3.1
 * better organization and neater presentation of external links
 * proper in line citations