GMNA-GM-E172-1994.pdf

. GENERAL MOTORS ENGINEERING STANDARDS I Englneerlng 1 METRIC TYPE AHS SELF-PIERCING NUTS El 72 HOLE TO BE LOCATE AT TO PILOT WITHIN 0.25 DIA TRUE POSlTlON RELATIVE TOLERANCE ZONE (RFS) 1.5 MA% GAP (REF) 7 (REF 25' (REF) PILOT TO BE LOCATED AT TRUE POSITION RELATIVE TO BASE OF NUT WITHIN 0.25 D I A TOLERANCE ZONE (RFS) - PILOT LENGTH AND WIDTH LIMlTS APPLY AT THE DETKL OF INSTALLED NUTS SHALL BE JOINED I N STRIP FORM BY TWO WIRES KNURLED OR COINED INTO GROOVES ON BASE W NUTS AND FURNISHED COILED ON REELS (SEE GEN SPEC) BURRS FROM CUlOFF MAY EXCEED TOLERANCE SHOWN BY 0 . 1 5 rnrn - 8 PLACES THE RESPECTIVE FEATURES CENTERUNE THROUGH STRIP FORM NUTS N I dimensions art in mm I I M6 1.00 5.153 4.917 0.64 1.65 M6 11.00/ 5 1531 4.9171 0.64 I 2.29 6.6471 M8 11.251 6.9121 0.64 1 M8 1.25 6.912 6.647 0.64 M8 1.25 6.912 6.647 1.40 M101 i.50 8.676j 8.3761 1.02 I 2.29 Mi21.75/10.441/10.106/ 1.40 I 2.79 I 1 I 9.35 1 11.35 1 0.64 2.: 5.21 16.03 I 11.6111 1.36 I 2.C ! A 8.20 10.85 0 64 1.5 9.35 I 11.35 I 0164 1 2.1 1 5.21 5.51 16.74 11.10 10.85 2.8 I D I 18.C3 ii1.61i11.36i 2.0 ! A I I 10.21 12.60 0.64 1.5 6.50 10.97 13.89 1.40 2 . 1 13.89) 15.241 1.02 2.; I 8.64 I 2 4 C 5 !15.651:5.31' 3 3 I C 10.57 ' 13.39 0.64 2. j 7.14 7.90 i 0 ' METRIC TYPE AHS SELF-PIERCING NUTS 0 A u ; u s T 1 W d M o ( o n A J F 1 u F I a s r s d AUGUST 1994 PAGE 1 El 72 Copyright General Motors North America Provided by IHS under license with GM Licensee=IHS Employees/1111111001, User=Japan, IHS Not for Resale, 06/23/2008 23:59:40 MDTNo reproduction or networking permitted without license from IHS -,-,- 1 GENERAL MOTORS ENGINEERING STANDARDS I Englneerlng I METRIC TYPE AHS SELF-PIERCING NUTS El 72 1 GENERAL ?lac Metric Type AHS ( H i e S S S ) Stlf- Piercing Nuts covered by t h i s standafd arc intended for use in applications requiring ptnnanently pre-installtd internal mnlti- Umad fasteners in sheet md components where strength capabilities execling those provided by comsponding T y p AH self-piercing nuts is necessary or where it is essential to obtain a flush mounting surfaa without employing an emboss- mcnt Sce the typical Typ AHS Nut installarions depicted in Figwe 1. 1.1 As implied by name. these products axe designed to be instalkd as a picxu nut wherein they product their own hole in panels of the thichesses spcclfied in Table 1 and are staked into plaa in the same opemtion. The combined press funaions minimize or em entircly addhional handling or second- ary operations, such as welding, or the mounting of clip assemblies. thus reducing innallation costs. NOTE: Each of the respective types of self-piercing nuts =quire specifc tooling to i n s t a l l them Therefore. proper care must be exercistd in the selection, proMtmcnt and distribu- tion of nuts by F number to insue they are compatible with existing or contemplated innallation equipment available at the assembly locations. 2 REFERENCED STANDARDS. GMSIOM GM6103M ANSI B1.3M 3 NUT FORMS. As designated by part number, most nut sizes are avaiiabk in either loose U) form or snip (on wirc) form. to best suit the needs of the nut installation facilities. Snip form nuts are supplied coiled onto reels, with the quan- tity of nuts per ne1 king subject to agreement betwan the nut manufacturer and the purchaser. Where the nuts arc available in both forms. conmlrations should be conducted with appro- priarc manufacturing operations to asccnain the applicable parr number for a given application. 4 MISCELLANEOUS DIMENSIONS. The seating plane of nut shall bc perpendicular to the axis of the threaded hole wit.hin 2'. The base surface of nut shall be sufficiently flat as to prevent rocking when placed on a surface piate. 5 THREADS. Threads shall conform to internal memc coarsc series screw threads for mechanical faseners as pub- lished in Specification X100. Unless otherwise spccifcd. the acceptability of threads shall k determined by gaging in accordance with System 22 as shown in American National Standard. ANSI B1.3M- S a w %ad Gaging Systems for Dimensional Acceptability of Metric Screw Threads. The h a d minor diameter limiu must bc mainmined from the pilot face to a depth quivalent to one-third of the a& nut thick- ness. The minor diameter at the base of the nut shall not exceed the spccif1ed maximum limit by more than the equiva- lent of 10% of the basic nut thickness. 6 MATERIAL Nuts shall be fabricated from any cubon =eel that will permit the nms to pierce panels of the thickness ranges spccificd without deformation of the nut threads and be capable of meeting the proof load requirements tabulated below for the respective nut and blank sizes. Nominal Thread Nut Size Pitch M5 M8 1.25 M8 1 -0 M6 1 .o M6 0.8 1 . 7 5 M12 15 M 10 1.25 M8 1.25 Nut Blanl Ske A D A . E B S C F - Nut Proof Load, kN1 13.0 18.4 18.4 34.4 34.4 34.4 54.5 80.1 ' Proof load detnminations. whem required. shall be made in accordance with the test procedures set forth in the GMSlOM speci5cation. 7 FINISHES. As designated by part number. the nuts shall be furnished plain, plated or coated in accordana with the rcspcctlve GM specifications. 7.1 PLAIN STEEL. Plain f s h steel nuts shall be clean ( f n = e of dirt, rust and proassing compounds) and, unless oth- e k s e designated by the purchaser. coated with a light oil film 7.2 DETERMINANT OF PLATING THICKNESS. The thickness of the plating or coating on nuts shall be as dctermincd on the side of the nut. Salt spray requirements shall not apply to the threads of nuts nor to the base of strip form nuts in the area of the carrier.wircs which arc subjected to additional processing following the plating operation. 8 WORKMANSHIP. Nuts shalI be free from burrs, scams. laps, loose scale and any other applicable surface dis- continuities exceeding the limitations set forth in the GM6103M specification, Surface Discontinuities on Nuts. 9 DESIGN CONSIDERATIONS. The following general information is included in these specifications to guide the designer in the appropriate selection and application of these fasteners and aid in their proper installation 9.1 APPLICATION. Type AHS nuts are designed to be installed with specialized tooling as pierce nuts wherein they produce their own hole in panels or parts having thicknesses within the range spccifkd and are stakcd into place in the same assembly operaxion. They should be considered for use in all mass production and other applications requiring this type of fastener wherever the cost of the specialized tooling is justifi- able. As indicated in Table 1. it is recommended the tooling used in conjunction with metal thicknesses falling within the lower portion of the panel range produce a corner stake in addi- tion to the n o d dovetail stake as depicted in Figure 1A. For . L E I 72 PAGE 2 AUGUST 1994 Copyright General Motors North America Provided by IHS under license with GM Licensee=IHS Employees/1111111001, User=Japan, IHS Not for Resale, 06/23/2008 23:59:40 MDTNo reproduction or networking permitted without license from IHS -,-,- '.* , 1 . i . 8 I I I 1 GENERAL MOTORS ENGINEERING STANDARDS Englneettng METRIC TYPE AHS SELF-PIERCING NUTS El 72 M6 M6 . M8 M8 M8 M10 M12 1 .o 1 .o 1.25 1-25 1 .z 1 5 1 . 7 5 L A D A E B S C F metal thicknesses within the upper portion of the range the 9 . 1 . 1 Other Applications. Where rtquired, low pressure dovetail stake as shown in Figure 1B is considered adequate. water sealing, prevailing torque. and multiple panel piacing The tooling setup should be such that, when the nut is installed feanucs can also be provided 'he nut manufacturrrs should into the panel, the top of the pilot w i l l be flush with or below be conmlted for details and Itcommcndations. the plane of the adjaent panel surface as i l l u s - in Figun 1 . TABLE 1 (mm) Pand Thickness Range' Nut I n s t a l l e d Wlth Backup Nut Installed With Dovetail Nominal Nut . Pitch Nut Blank Size Size Stake Corner Stake From 229 1 . 1 5 1 . 1 4 0.64 0 . 8 M5 'Ib From 'Ib - L 0.64 0.64 0.64 0.64 - - - 1 . 1 4 1 . 1 4 1 . 1 4 1 . 1 4 - - I 1 . 1 5 1 . 1 5 1 . 1 5 1 . 1 5 1 .a 1 . 0 2 1.40 1 . 6 5 2 . 2 9 1 . 6 5 2 . 2 9 2 . 7 9 2 . 2 9 2 . 7 9 I Nuts may also be suitable for application'in panel thicknesses outside ranges tabulated, with controlled assembly tcchniqucs. However, the xuanufacturu should be consulted for recommendatlorn bcforr such dcvizuions arc spccifrcd. I r- I I I l I I C L- I IL I i BACKUP CORNER STAKES ! FIGURE 1A - INSTALLED FIGURE 1 B - INSTALLED ' WITH DOVETAIL AND WITH DOVETAIL STAKE I 9 . 2 PUSH-OUT LOAD. The pushout l a d shall be the fora in newtons, applied parallel to the axis of thread o f an i n d e d nut in a dircaion against the stake, required to push the nut h e fiom the panel when the nut is antrally located over a hole in the tcst fixture of a diameter as given in Table 2 for thc respective nut blank size. It is generally recommended an illus- tration incorporating the clearance dimension and push-out force note as depicted in Figure 2 be shown on assembly drawings that entail pierce nut attachments. The push-out forces listed in Table 2 for the respective nut blank sizes assembled into minimum metal thickness will provide inspec- tion criterion for determining that nut has been adequately installed to withstand any loads involved in assembling the mating fasteners. Where it is desired to spcclfy the minimum push-out load on the assembly or installation drawings for quality assurance purposes relative to too% and processing setups, erc., the appropriate push-out force values should be determined on the basis of actual production and installation conditions and, insofar as possible, kept in line with the rcquircmcnts of the f i n a l assembly operations. Pushout fora increases as panel thickness increases, and is influenced by the panel material selection. Nut retention testers and fixtures for nondestructively checking the push-out resistance of installed nuts may be procured from the nut manufammr. i E1 72-001 (8/94) a FIGURE 1 - TYPICAL TYPE AHS N U : INSTALLATIONS 0 * u G u s T 1 e e o G s a a l M g . . c o r p a s a n A J m # l t a AUGUST 1994 PAGE 3 El 72 Copyright General Motors North America Provided by IHS under license with GM Licensee=IHS Employees/1111111001, User=Japan, IHS Not for Resale, 06/23/2008 23:59:40 MDTNo reproduction or networking permitted without license from IHS -,-,- I GENERAL MOTORS ENGINEERING STANDARDS I Engineering i D METRIC TYPE AHS SELF-PIERCING NUTS El 72 NUT MUST NOT PUSH OUT FROM PANEL WHEN FORCE OF (1) N IS APPLIED IN DIRECTION OF ARROW '1) See Toble 2 E172-002(8/94) FIGURE 2 - ASSEMBLY DRAWING DETAIL TABLE 2 - PUSH-OUT RESISTANCE LOADS Nut Blank Size For Nut 1 l e A D B E C S F mm 4 . 1 5 M n 4.03 -0.00 -0.25 0.64 890 24.00 0.64 890 24.00 0.64 , 890 28.00 0.64 890 28.00 1.02 890 32.00 1-40 890 28.00 1.4 890 40.00 10 DESIGN GUIDELINES. 10.1 CENTER TO CEVIER DISTANCE. The minimum Center to center spacing between adjacent nuts for the respec- tive nux orientations shown i n Figure 3 are spccif1ed in Table 3. 10.2 FLANGE AND EDGE DISTANCES. Using standard tooling, the nus may be placed inside pockets and adjacent to upturned flanges and panel edges. for the respective nut orien- tations as depicted in Figure 4. within the recommended minimum limits given in Table 4. 10.3 UNCONVENTIONAL APPLICATIONS. Where the placement of a pierce nut is &SM at a location which cannot be installed with standard tooling and press operations such as an inside vertical surface of a “V shaped pancl as shorn in Figurr 5, special purpose tooling is available. Consult the nu! manufacturer for rccommcndations. I I I FIGURE 3 - CENTER TO CENTER SPACING TABLE 3 - CEHTER TO CENTER DIMENSIONS (mm) Type of Ibollng' A I B MID' M D ' standard - Mechanical standard - Rleumaric Standard - M12 Mechanical Standard - M12 Pneumatic 57.2 76.2 6 6 . 7 88.9 38.1 38.1 50.8 50.8 I Under certain design conditions &er to center distances ing. In all such cases. however. the nut manufacmr shall be consulted in regard to the advisability and extem of devia- tion. ACSS than those tabulated may be obtaimd with special 1001- TABLE 4 - FLANGE AND EDGE DISTANCES (mm) m of 'Iboling Mn1 I Mid I Max' 1. Max' A B C D I I I Standard I 28.6 I 19.0 I 69.8 I None Values shown are recommended minimums for all nut sizes. However, through various tooling design combinations these dimensions may be reduad beyond k t s given. In a l l such cases. the nut manufacturer should be consulted in regard to the advisability and extent of deviation. max limit applies for standard tooling. Special tooling is available for higher flange heights. No max limitation on standard mechanical tooling. Limitations do apply on standard pneumatic tooling. Consult nut manufacturer for recommendations. PAGE 4 AUGUST 1994 Copyright General Motors North America Provided by IHS under license with GM Licensee=IHS Employees/1111111001, User=Japan, IHS Not for Resale, 06/23/2008 23:59:40 MDTNo reproduction or networking permitted without license from IHS -,-,- METRIC TYPE AHS SELF-PIERCING NUTS El 72 W = 1 . 5 OR LESS. 2 x W I F W I S GREATER THAN 1.5 NO MAXIMUM 2 x W PREFERRED E172-004(8/94 FIGURE 4 - FLANGE AND EDGE DISTANCES 11 JOINT CONSIDERATIONS. The hole provisions i n the panel or component to bc assembled must also be consid- exui i n the overall &sip of the atrachmenr. set F i p 6 . in mating panels the rccommcndcd maximum clearance hole size. K. should not exceed nut pilot width. h mating panels the TCG ommended maximum slot width, L. should not exceed nut pilot width less 0.8 mm. 11.1 For applications requiring normal or close clearancc provisions, hole sizes and slot widths should conform with general praaiccs. 12 GENERAL INFORMATION. This standard was originated by the GM Fastening Cornminoc i n October 1991. FIGURE 5 t MATING PANEL YNG PANEL r”-? ! i RADIAL POSITION OPTIONAL AROUND I I CENTEi7LINE OF NUT , FIGURE 6A - 1 CLEARANCE HOLE MAXIMUM SLOT WIDTH SHOULD BE 0.8 mm LESS THAN NUT PILOT WIDTH IN ANY RADIAL POSITION FIGURE 6B - SLOTTED HOLE 172-006(8/9*) FIGURE 6 - MATING PANEL HOLE PROVISIONS O N G U 3 1 8 8 d o a a d M D b n A l - AUGUST 1994 PAGE 5 El 72 Copyright General Motors North America Provided by IHS under license with GM Licensee=IHS Employees/1111111001, User=Japan, IHS Not for Resale, 06/23/2008 23:59:40 MDTNo reproduction or networking permitted without license from IHS -,-,-