B-114BMitutoyo operates a policy of continuous improvement that aims to provide the customer with the benet of the latest technological advances.Therefore the company reserves the right to change any or all aspects of any product specication without notice.B-114B■ Guidelines for Self-made FixturesA micrometer head should be mounted by the stem in an accurately machined hole using a clamping method that does not exert excessive force on the stem. There are three common mounting methods as shown below. Method 3 is not recommended. Adopt methods (1) or (2) wherever possible.(Unit: mm)■Graduation Styles●Care is needed when taking a reading from a mechanical micrometer head, especially if the user is unfamiliar with the model.●The "normal graduation" style, identical to that of an outsidemicrometer, is the standard. For this style the reading increases as the spindle retracts into the body.●On the contrary, in the “reverse graduation” style the reading increases as the spindle advances out of the body.●The "bidirectional graduation" style is intended to facilitate measurement in either direction by using black numerals for normal, and red numerals for reverse, operation.●Micrometer heads with a mechanical or electronic digital display, which allow direct reading of a measurement value, are also available. These types are free from misreading errors. A further advantage is that the electronic digital display type can enable computer-based storage and statistical processing of measurement data.■Thimble Diameter●The diameter of a thimble greatly affects its usability and the "fineness" of positioning. A small-diameter thimble allows quick positioning whereas a large-diameter thimble allows ne positioning and easy reading of the graduations. Some models combine the advantages of both features by mounting a coarse-feed thimble (speeder) on the large-diameter thimble.Normal graduation styleReversegraduation styleBidirectional graduation style 05045502025455009080102020801090502025Mounting methodPoints to keep in mind(1) Clamp nut (2) Split-body clamp(3) Setscrew clamp Stem diameterø9.5ø10ø12ø18ø9.5ø10ø12ø18ø9.5ø10ø12ø18Mounting holeFitting toleranceG7+0.005 to +0.020G7+0.006 to +0.024G7+0.005 to +0.020G7+0.006 to +0.024H50 to +0.006H50 to +0.008PrecautionsCare should be taken to make Face A square to the mounting hole.The stem can be clamped without any problem at squareness within 0.16/6.5.Remove burrs generated on the wall of the mounting hole by the slitting operation.M3x0.5 or M4x0.7 is an appropriate size for the setscrew.Use a brass plug under setscrew (if thickness of xture allows) to avoid damaging stem. Face A


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