INVENTORY AND ACCOUNTABILITY

Figure 2-30.—Depth micrometer sleeve and thimble scales. used gives you the total depth of the hole, rcccss, or groove that was measured. SELECTING THE PROPER MICROMETER The types of micrometers commonly used are made so that the longest movement that the micrometer spindle or rod can make is 1 inch. This movement is called the range; for example, a 2-inch micrometer has a range of from 1 inch to 2 inches, and can only measure work with a thickness or diameter within that range. Therefore, it is necessary to first determine the approximate size, to the nearest inch, of the work to be measured and then select the proper size micrometer. The size of a micrometer indicates the size of the largest work it can measure. CARE OF MICROMETERS Keep micrometers clean and lightly oiled. Make sure they are always stored in a case or box when not in use, to protect them from damage. Never clean any part of a micrometer with emery cloth or other abrasive. The measuring tools that have been described in this chapter are the ones that you, as an ABE, will routinely usc while performing your assigned duties. You may, however, occasionally be required to use other less commonly used measuring tools. Some of these arc the dial indicator, telescopic (snap) gauge, the vernier caliper, or screw thread gauge. The description of these tools and instructions for their use can be found in the training manual Use and Care of Hand Tools and Measuring Tools, NAVEDTRA 12085. INVENTORY AND ACCOUNTABILITY All measuring tools will be marked in some manner, etched, stenciled, etc., to comply with standard inventory instructions. These standard instructions may be found in OPNAVINST 4790.15 Some measuring tools such as tapes and calipers may be part of a specific tool box inventory. Other precision measuring instruments such as micrometers, snap gauges and vernier calipers will normally be maintained in the division’s central tool room. Regardless of the tool’s permanent location, it is always the user’s responsibility to maintain, care for and use the tool properly. Damage, loss, or an improperly working tool should be reported immediately. Loss of a tool becomes especially critical when working on or around the catapult or arresting gear machinery. The tool may be “lost” in the machinery and, if not found, may cause catastrophic damage to the equipment and serious injury to personnel. Always double-check the inventory ensuring every tool is accounted for upon job completion. The proper tools will help you maintain your equipment but only if you maintain your tools properly SUMMARY This chapter has introduced you to some of the most often used measuring tools and the techniques for using them. Selecting the proper tool; using and maintaining the various tools; and inventorying the tools have all been discussed. By thoroughly understanding and comprehending this chapter, you, as an ABE, will be able to perform your daily duties more efficiently and safely. 2-12