METRIC THREADS - Willrich

1 6G 6e 6H 6f 6h 6g Basic Pitch Diameter Max ax MIn Min MEXTERNAL PRODUCT INTER AL PRODUCT NBasic Pitch Max Min MIn EXTERNALL PRODUCT Diameter Max PRODUCT INTERNA 3h 4h 5h 6h 7h 9h 8h 4H 5H 6H 7H p is not enough information to clature for the gage or the product is Mris. s to remember about METRIC THREADS , is ta sizee. A proper and complete nomenecessary. een engineered to product. he METRIC screw roduct tolerance or THREADS is the opposite of the inch design. With METRIC screw THREADS thdesignation for the clroduct tol The most common METRIC product sthread i external product,the clasoduct, which crebly scenario to the inch lts' fit. Companies that etric gages, usually'6H' ages for internal g' ring et plug gages eads, se this compriseic gage market. METRIC Allowances he 'g' & 'H' are commonly enoted by the case of the letter sed, lower case for external , and pper case for internal.

2 GSG Ask for thread Se100 8H ETRIC THREADS The best way to explain and understand metThe first and one of the most important thinthat, like inch THREADS , knowing the manufacture a gagc THREADS is by comparison to inch threadgn METRIC THREADS have ballow for much varia-tion while still being able to be considered a standardizedTthread has five stand-ard internal product classes and seven standard external pro-duct classes. Thepmanufacturing window for METRIC screw e larger the number ass, the larger the a very similar assem2A / 2B 'Nuts and Boperance. crew and ss the class 6gs 6H internal pr and ates becauthreadstock mplug g stock class THREADS and '6for external thrs 80%+ of the metr Tconfused with the unified method of denoting internal and external of 'A' & 'B'. Here the METRIC uses a method that is not present in the inch series.

3 The internal and xternal THREADS in metrics are eduu Copies of this material may be obtained fromminar Book # SG Glastonbury Southern Gage Page # 13 M8 X 6H * METRIC series Nominal size Th pitreadch Internal product * *Class of fit * Modification (LH, special PD, etc.) * * g would denote an external product The letter used denotes tlowance adjustment applied to the basic we see a difference in the inch nd METRIC systems. In the Unifble axternal thread . For METRIC , you can apply allowances to the internal allowance available for external , the 'f' being more, and the 'e' being the greatest allowance. etric DES GNAT O mee M to the s canN foN forread that in signation precedes is pronounced as by . In thenominal size is followed by ch, whereas in METRIC the inverse of the actual distance from one thread to the next, oduct pitch , is the to the product major and minor diameters.

4 ENRE EXAMPLES itch) - (Cla(Allow.) (Mod.) M4g LH M6 D5 CopiesAsk fohe amount of applied to the ealsize. For external THREADS , allowances available are 'e, f, g, & h'. For internal THREADS , allowances available are 'G & H'. Here again also. In both the internal and external the 'h or H' signifies an allowance factor of zero. The 'G' is the only allowance for internal THREADS and the 'g' is the smallest aied, there is nd it is only only one allowance availaM The nomenclature of THREADS begins with the lettThis is the designation sthe METRIC series. Other may be added after thshowing modificationsstandard METRIC series. Thibe compared to the UUnified National, or National in the English thnomenclature. Notice metrics , the series de IINetric r M. howing letters r the nominal size and pitch, unlike in the inch series, which follows the nominal size and pitch.

5 The nominal size is the first number that follows the METRIC series designation, followed by the pitch. The nominal size and pitch are separated by the letter X , which follows the nominal size. Following the pitch is the class of fit. The designation that denotes internal or external also signifies allowance. When the class of fit is specified with two different classes, such as 4g6g, the first one, 4g, is the tolerance applied to the pr inch series the the THREADS per diameters, and the second one, 6gtolerance appliedinthreads per inch, the pitch, the METRIC NOM(Type)(Size) x (P CLATU s ) of this material may be obtained from GSG r thread Seminar Book # SG100 Page # 14