{VOC 621.887.6 : 62-472 : 001.4 : 003.62: 620.1__ DEUTSCHE NORM Spetember 1981 Circlips (retaining rings) for bores Normal type and heavy type 1e) fir Bohrungen; Regelausfihrung und schwere Ausfihrung Supersedes DIN 472 Part 1/03.65 and DIN 472 Part 2/03.65 and partially supersedes DIN 995/01.70 Sicherungsringe (Hal As itis current practice in standards published by the International Organization for Standardization (ISO), the comma has been used throughout as a decimal marker. Dimensions in mm Contents Concept -- . eo Dimension letters, symbols Dimensions, designation, design data Material. . Finish... Testing... ‘i ‘Load-bearing capacity Shape of groove Fitting the cirelip 1 Concept Cirelip within the meaning ofthis standard are retaining rings for holding structural components (0.9. rolling bearings) inbores. They ae given an eccentric shape, ar fitted with spring retention in grooves and are suitable forthe trans- mission of axial forces (ee inthis respect clause 7) Dimension letters, symbols radial width of the lug beam (radial width of circlip opposite the aperture} distance between measuring plates for testing spiral flatness bore diameter groove diameter external diameter of the circlip not under tension ‘minimum symmeteicat diameter of bore during fitting diameter of the lug holes modulus of elasticity load-bearing capacity of groove at a yield point of the grooved material of 200 N/mm? (see subclause 7.1) load-bearing capacity of circlip with sharp-edged abutment of the pressure part (see subclause 7.2) load-bearing eapacity of circlip for abutment with edge chamfering distance g (see subclause 7.2) yield point edge chamfering distance of the surface abutting against the circlip, distance between the plates when testing conical deformation Reproduction even in pert, oly withthe exci permission ofthe ON Deutch ‘groove width ledge margin ‘curvature in the groove base or test jaws thickness of the circlip groove depth with nominal sizes of dy and da Service ot 88 Continued on pages 2 to 12 Sagpan gin Gar Bonnar Nooo Dinara Ena Pr oat abe cox crorePage 2. DIN 472 3. Dimensions, designation, design data The circlips do not need conform to the illustration; only the dimensions specified must be adhered to. unloaded shape of ring at manufacturer's discretion bore Figure 1 Figure 2. Detail of X dys 300mm dy = 170mmat dy = 25mmat manufacturer's diseretion manufacturer's discretion Ve aye Sry a oe FAUKTALS [ott Figure 3. Values for peak-to-valley height for groove base and loaded edge must be specified in each case. Designation of a circlip for bore diameter (nominal dimension) d = 40 mm and circlip thickness s = 1,75 mm: Circlip DIN 472 — 40 x 1,75Table 1. Normal type DIN472. Page 3 Sam lip coe Seopaneniny oe) ‘eter TT ‘Nominal 4 Weight of || Sans? Nomina | 6 ae | 1080 | aay male | w | de | Be | re | | Pee| clorcng “on 4 maf 8% a | tn wn | an x | omn'3266 2 [oe |e n ‘a -grfos jaz joo] 3 | 086] 200] 08 | 1.20 2 los | 1 24 |ernfoe |o2 |o6| 37 | 096) 200/05 ' 1,50 oft wos] [32)ral ya To. oz [oe| 33 v0e| 400) os] 2.20 it ne] _[aapus [2 14 oz [os] «1 | 117] 400) 05 | 2.0 wef] fe teeteehia 28 ozs] 08| «9 180] 400) 08 | 2.30 wht var] [ae [ua 136 /'3"[11 joa toa] sa] ano] «20/as[ 220] 8 “ht wr] [a7pee 14s [ovis joa [oa| 62 2261 as0] as| 230 shh vez] [a7p2 wer] [tr fossa] 500] 05] 2.30 ht nal [ael? wea] [ros [az wh] fsa} [asf ma] [ts joa [v2 weft ves} [astaat? | | [eos [a5 it 205 |soua| 8.1 22[ 2 20 |roraitst [05 | 18 ~ 2 |r as] °"[42)23[2 21]. [os | 18 [ait [ps| 2 2 ut fos (1s. zi m5 | 2 w|i jos [1s 2 269 2 25.2 1.3 [06 | 1.8 5 209 2 262 |-on|13 [08 [18 | 26 2a [2 272 |enaltd [06 | 18 2 201 2 zea] [ta [or [aa - = zi] [asia [2 ma] [13 [or [20 3 m4 62/32/25] 210 |327) [13 los] 26 2 ma] (sa[aztas| 221 [aa7) fia loss) 26 a 36 |'2h/sayaalas| 320 [957] |r Joss) 26 = fa] (safae[as| ase [a] hes [3 EI sas] [sa[as}os| 370 [oe _fselie fi [3 [oar [see] [es[sel2s} ar [ae jonalis jr [3 = wos| [ss[arjes| a0 [| fief [3 a as] [se[aa/25| 470 [as 1238 @ 255 |'%[50]41] 25] 540 [45] as] 38 ‘s ws] [67[e3[ 25] 600 [475] as 38 7 wos] [e4/4a[ as} 610 | «os as] 38 [oa ss| [64/45] 25] 670 [20s | asl 38 so 2 54,2 65 | 46/25 15 [45 2 sz| [67/47] as aas|us [4s se sez| [eas [as sli [5 2 [eoz| [eelsiles a.is)us [46 oe? @22| [6o|52/ 25 ais [4s ° eo iz 642 [346] 7.3 [54 | 25 +geofaas|is [as 62 [2 Bor] 68.2 73/55 | 25 | losiaf2.a5 [5 | 45, ee 2] [73 aust [4s 28 [eo2| [78 rnes|ts [45 [ces] [rs| De resis [4s 2s) [ms| [a ress | [fas | [res| [78 | [assis 7s (25 | 795° 78 | feeshs. 7) Dimension sal not exceed dimension amex 2) Soe mbcinute 81 3) See sbcleuse 82 4) The sppiementary data apply ont 1 eelp ia sorog tel in secordonce with DIN 17222 Note: dg calculated from: dg =dy — 2,16Page 4 DIN 472 Table 1. (continued) Clip ] Groove ‘Supplementary date 4) T T ‘Nomina ‘ae of ofa [oe fanfas | 4a alae] me | « [8s BE[mw| x [mn | = msl wn | in DIN'5256, 25 | 82.5 3 20.4 | 81 45) 60,1] 62,3] 1225 | 25 25 | So 55 a [0 | a8) 53] 21| 765] 1209 | 26 ” 25] #75) 3 [0 [ass sa] 641] 766] 119 [25 | 3 35253] 635 53] 96.9) 705] 2014 | 3 3 as| 760 | s18| sal ona) 3 3 95,5) 35, 31,0__| 93,5) 53/19 3 3 Sue 975 35] 320 | 955) ‘sa 737 3 a] [t005+334 as] 350 | 985) 53| 765) 3 2] [o [aslas|— 270 [ions sa] 7 [wale [3] 3 aa] ea[3s| 980 [1055 $3] 208] #91] 100 | 3 7 a 95) 85]95| 550 [105 @ |e [ioas[ as] 9 4 95] a7|a8| 60 [100 [es [ia [wo [o « 9s] a9]35| 00 [112 | [ee ]is[ae [a 10 [* oats [35] ess [vie eo [eal [ais [3 ila os) ei]35| 720 [16 [oo ue [ae [2 ws ja) [ma] —fosfestas| ms [ie [oa [az [woo [3 4 127 nm [97/35] 70 [124 | 6 | s6a|t27 [08 | 3 a) fx] fa fio [« [790 [28 6 3 a] fer] fro [20 [se g 2 a] 112/105 | 4 240 1139 6 3 « ia[toa[e | e715 [ae € 3 ra ualiosfa | 93049 6 3 * 2 |rial« [i055 ral raea|vor_[aa8 [3 ana 2 [ials [107 [160 | [206 [328 | 35 + a [ise[« | 110 [165_| a [321] 35 4 13 [ne]« | 125 [170 a [310 [35 « nas |i2)4 | 140 [175 | eas |e [ 35 « 135|127| «| 150 [190 fae 351_ [35 2 raaitaa[ 4 | 165 [10s 00 [307 [as ‘ {iaaltaa| « [170 [100 205 [ua [ 35 = + raaliae|« [175 [105 ast [o00 [35] 575 zelraalras| «| 10a [200 258 | 290 [35] 555 200 oes} reali [4 | 195 [206 2e5 [925 [35] 550 zo [san] faze fe | a0 fe |" 2 [woalsn [oor [os 20/6 faz nazi [a | 318 [226 15)3 | 9 349, 4 [850 [zo Js] fe] fraajie Te [a0 fess | ssl | 9 z002|305 + [a0 zo fs] fase] [mala fe | os foes | [ssl | 0 [2102 |a00 a [ns [-zs0—[s—| . [262] fiaalsa [a | a80 [ass] [ss|_| 0 [zz02| 306 + [780 260 [8 | °|a75 162/16 [5 | 375 [268 5.15 |6_|12 59 4 [00 20 [5 205 _|*28,]162|16 [s | 398 [278 |'9"|6.16|4 [12 era [sie | « | 770 zo [s | [25 | [rs2|te [5 | «00 owofg.5/4 [12 [206 509 [ 9 | # [760 zo [5 [aos] frealie [s [15 [ave | [ss|e [2 [756 Jers | oe [4 [715] so [s | _[sts | _|rsalte [> | eas [ooo] _[s.s5|e [12 [266 Joos [oso [+ | 00 For 1,21, 9) and) we poe 3DIN472 Page 5 Table 2. Heavy type = oe [seo Sasoreny dow oe Nomina “ grt eo nmma| «| as |e [anf ae RR ef fae) ae | me |e | tm] lie Mor | [ae] [Beene] ~ [en] = nn | [ow 1 | om’ 2e6 hs} (as) asl? | a las [rs 108] a0] veo || 500 zs] [aos] [erlzale los [us| rat | 600] 180 [1 | 6.0 mis] [aael3teals [2 jos [re[ra7[ 270] 2.7] | 720 ois] [ael [s [arl2 ie] 145 | Bool aa8 [| 720) wis} [el [silarl2 te] 183] eao] 216 [11 720) [cas] [aoa —[salaa|2 21/169 [105 700] 30 zai] [sslaal ia aires [na wpa B sea] _[s7]z4l2 37 ze[a [we] a4[1 | 720 ies 3]: 357 ze [216 [va | 366 [18] we % a8 a 3 [za |ie0 is | 870 7 39.8 30_|*3%*| 3 | [ioe 18] 8.80] A “oa ‘oo a [a7 aes is | 9.0 [ca | ass 2] 3a] 263270 | sna]? [108 “ala ) ass) 28 a5 38| 270 204 | sas |2 [0 fe | Cans a8 38/903 [902 | ees [2 [107 [472 _|.8or) 505 298 [38| sa [314 | 5x0 |2 [108 “so [25 a2 3 45/342 [405 | 055|2 [190 sees | [sea { a as[s50|e20 | oe] 2 shes | [eee 8 45 [982 [eas | 047 [2 [108 eos a 45[@21 2 o ses] [esa] oar as| 09 2 eis] [eaz|tsie| 68 [ora 45 | 46,7 [518 | 174 8 [2 | Soa) 725] 7 45 [405 [585 | 1785 | 7] [as 73 as] sia [ssa [in mje) [es 75 45] 27 [560 [172 | [sl 7 45[ 558 |eo0 | 170 wo je] Lass 332 | ea] 53] 60 [768 | 708 [ese] [eos] [azpratas] see eos]... sa] eae res [258 ofa ]-$, [oss |ztio [re [as] as [ms], 53] 60 [eso [ase] ‘s sje] fioos| fis] ar fas] ser | sas 53| 733 [oss [7 [a [seo | ooo] [ross] _fostaelas| sor [ross 53/76 |oa1 [a [3 [550 For 71,9) sn) we sePage 6 DIN 472 4 Materi €67, C75 or Ck 75 spring steel in accordance with DIN 17 222 (at manufacturer's discretion} ‘Table 3 applies in respect of the hardness: Table 3. Nominal diameter of a Hardness over: up to = 48 470 to 580 Vickers hardness (corresponding to 47 to 54 Rockwell C hardness) 48 200 4435 to 530 Vickers hardness (corresponding to 44 to 51 Rockwell C hardness) 200 300 390 to 470 Vickers hardness (corresponding to 40 to 47 Rockwell C hardness) ‘Hardness values converted in accordance with DIN 0 160 Other materials on agreement. 5 Finish Circlips must be without burr. Circlips are normally supplied corrosion-proof in accordance with table 4 (at manufacturer's diseretion). No special is concerning this condition on delivery must be stated in the designation of a circlip. Table 4. Anti-corrosion treatment of cit Sort No, Type of anti-corrosion treatment Corrosion resistance Phosphatized and oiled in accord: 1 | ance with DIN 50 942 'No sign of corrosion permissible rbot: Znph r= dtter 8 hours of exporre Symbol: Zaph =f __|_ Sate spray test according to Blackened and ciled | aN RosaTt ss 2 | thermally or chemically) Burnished and oiled in accord ‘ance with DIN 50938 Protection factor in accordance 3 with DIN 50 638, December 1973] eee edition, subelause 5.2. Symbol: br Af Ifa particular anti-corrosion treatment is required which is different from that specified in table 4, the designation of the circlip must be supplemented accordingly. For platings, the symbols according to DIN 267 Part 9 apply, ¢.9.: Circlip DIN 472 — 40 X 1,75 — A3K In the case of mass plating of circlips in a drum or bel, itis not possible to maintain closely toleranced plating thicknesses. ‘Attention is drawn to DIN 267 Part 9 regarding the danger of hydrogen-induced delayed brittle fractures in the case of circlips with electroplated surface protection, ‘The upper limit of the circlip thickness s may be exceeded according to the film thickness of the plating required in the case of circlips with electroplated surface protection. This must be taken into account when designing the groove.DIN 472 Page7 6 Testing 6.1 Testing the material Vickers hardness test in accordance with DIN 50 133 Part 1. Rockwell hardness test in accordance with DIN 50 103 Part 1 In cases of doubt, the Vickers hardness test applies. 6.2. Bond and fracture test “The etng of hn clip for cctley must be cared out in acordance with gue 4, . Ae / ‘One halt of the circlip is clamped between two jaws, of which one has a radius equal to the thickness of the circlip. The circlip is bent through 30° by repeated light hammer blows or with a lever, following which there must be no fractures or cracks in the circlip. The circlip is then further bent until fracture occurs. The fracture surface must reveal a fine-grained structure — 6.3. Testing the deformation 6.3.1 Testing the conical deformation ‘The circlip is placed between two parallel plates and loaded in accordance with figure 5. The distance h —s measured under force F must not exceed the maximum value stated in table 5. iF Figure 5. Testing the conical deformation Table . Nominal diameter Force Fin 25% Chal Normal Heavy over upto type type rs = z 20 60 2 38 40 20 »x 003 38 a2 Cy 120 2 160 | ) = fad bx 002 150 300 150 300Page 8 DIN 472 63.2 Testing the ‘The circlip must fall through two parallel, perpendicular plates with a clearance of ¢ in accordance with table 6. nhs Z bles Z ‘Nominal diameter yw of eircli e Y ° | NT. over wo | % [- 100 1BXS Zi 100 - 1axs ZAS = Figure 6. Testing the spiral flatness 6.4. Testing the function (permanent set and grip test) “The circlip must be inserted five times into a cone with a diameter of 0,99, in accordance with figure 14 and must then be fitted into a bore with maximum groove diameter d2 where it must be held under its own weight. 6.5 Acceptance testing For the acceptance testing the principles for testing and acceptance in accordance with DIN 267 Part § apply. ‘Table 7 applies to the features, while for the acceptable quality level table 8 applies. Table 7 Features Conical deformation Spiral flatness Function (set and grip) Table 8. Acceptable quality level AQL ") Tor testing of for testing for features |__ faulty pares 1 15, 1) See DIN 40 080 If other sampling plans are to be applied, this must be agreed at the time of ordering. For hardness testing DIN 267 Part 5, April 1968 edition, clause 5 applies {mn case of circips, the hardness test shall be regarded as a destructive test. 7 Load-bearing capacity ‘Acirclip connection requires separate calculations for the load-bearing capacity of the groove Fy and for the load- bearing capacity of the circlip Fp. In each case the weaker partis that which applies. The load-bearing capacities (Fy, Fa, Faq) listed in clause 3 contain no safety neither against yielding under static load nor against fatigue fracture under fluc- tuating load. There is at least twice the level of safety against fracture under static load.DIN472 Page 9 7.1 Load bearing capacity of groove Fy “The load-bearing capacity of the groove Fy in clause 3 applies fora yield point of the material inthe region of the bore groove of Regs, = 200 N/mm? as well as for the given nominal groove depths t and edge margins n. ‘The load-bearing capacity Fy for deviating groove depths t” (resulting from deviating bore diameters d and/or deviating groove diameters da) and yield points Riz, (previously 03) is directly proportional to the groove depth and the yield point "Rae 1 "200 P= Fy 7.2 Load-bearing capacity of circlip Fx ‘The load-bearing capacity of the circlip Fg in accordance with clause 3 applies to a sharp-edged abutment of the pressing machine part (see figure 7). Girclip QW Figure 7. Sharp-edged abutment Figure 8. Abutment with edge chamfering distance (chamfering or rounding) “The values Fag apply to an abutment with an edge chamfering distance g (see figure 8) ‘The two values Fy and Fag apply to circlip materials with a modulus of elasticity (E-Modulus) of 210000 Nimm?. If circlips of a different material with a different E-modulus B’, are used, then, for conversion, the load-bearing capacity of the circlip is directly proportional to the modulus of elasticity: If the existing edge chamfering distance g’ deviates from the values in clause 3, then, for conversion, the load-bearing capacity of the cirelip is indirectly proportional to the edge chamfering distance: & Reena) wae Fae Note: If Fag with small values of gis greater than Fp, then Fa applies, ing forces, because of too great an edge chamfering distance, cannot be accommodated, then a sharp-edged ‘of a supporting ring in accordance with DIN 988 (see figure 9). Wi If the exi ‘abutment must be created by mea — Supporting ring —Cirelip Figure 9. Sharp-edged abutment at the circlip using a supporting ring 8 Shape of groove 8.1. Groove diameter d ‘The groove diameters d specified in clause 3 are selected so thet the circlips are seated in the groove with pretension. dg min. Note: Larger groove diameters are possible if pretension can be dispensed with. The upper limitPage 10 DIN 472 8.2 Groove width m ‘As arrule, for the groove widths specified in table 1 and table 2, the tolerance zone H13 applies. With unilaterat power transmission, the grooves can be widened and/or chamfered towards the unloaded side. The groove width has no influ- tence on the load-bearing capacity of the circlip connection. Groove shapes and groove widths specified in-house are therefore possible, If the circlip is to be subjected to alternate power transmission on both groove edges, the groove width m must as far as possible, e.g. also by reducing the tolerance, be matched to the circlip thickness s. (For groove shapes, see figure 10 to figure 13). Whee YU, dX 028) 01) We} Wed A_t | 21 Figure 12. Figure 13. 83. Shape of groove base ‘A square shape is the normal type of groove base (see figure 10). The radius r on the load side must not exceed 0,1 5. (Other successful shapes of groove are shown in figure 11 to figure 13. In the case of a sharp-edged square groove, the notch sensitivity of the material used produces @ corresponding fatigue notch factor. 9 Fitting the circlip Pliers in accordance with DIN 8266 shall be preferred for fitting the circlips. ‘When fitting, make absolutely sure that the circlips are not overstrained i.e. are not squeezed further together than is necessary for insertion into the bore. If necessary, pliers with closing restriction (set screw) shall be used. The safest protection against overstretching is fitting with the aid of cones (see figure 14). [ _— Pressure bolt _—Circlip Cone Groove RY) —rousing Figure 14. Fitting with conesDIN472 Page 11 Standards referred to DIN 267 Part 5 Bolts, screws, nuts and similar threaded and formed parts; technical delivery conditions; testing and acceptance DIN 267 Part 9 Fasteners; technical delivery conditions; components with electroplated coatings DIN 988 ‘Shim rings and supporting rings DIN. 5256 Pliers for circlips for bores DIN 17 222 Cold rolled steel strip for springs; technical delivery conditions DIN 40.080 Procedures and tables for random sampling using qualitative features (sampling by attributes) DIN50.021 Corrosion tests; spray tests with different sodium chloride solutions DIN 50 103 Part 1 Testing of metallic materials; Rockwell hardness testing, C, A, B, F methods DIN50 133 Part 1 Testing of metallic materials; Vickers hardness testing, test load range: 49 N to 980 N (Skp to 100kp) DIN 50 150 Testing of steel and cast steel; conversion table for Vickers hardness, Brinell hardness, Rockwell hardness and tensile strength DIN 50 938 Burnishing of iron material; procedural principles, symbols and test methods DIN 50.942 Phosphatizing of metals; procedural principles, symbols and test methods Further standards DIN. 471 Circlips (retaining rings) for shafts; normal type and heavy type DIN. 983. Circlips with tugs (retaining rings) for shafts DIN. 984 Circlips with lugs (retaining rings) for bores DIN 6254 Pliers for circlips for shafts DIN 6799. Lock washers for shafts Previous editions DIN 472: 12.41, 11.42, 01.52, 01.54%; DIN 471 and 472 Supplement 1: 01.45, 03.54x; DIN 472 Part 1: 03.65; DIN 472 Part 2: 03.65; DIN 995: 01.70. Amendments ‘The following amendments have been made as compared with DIN 472 Part 1, March 1965 edition, DIN 472 Part 2, March 1965 edition and DIN 995, January 1970 edition a) standards combined bb) contents revised and extended (see Explanations) Explanations ‘The present revised edition of DIN 472 supersedes DIN 472 Part 1 and Part 2 and parts of DIN 996 where these concern circlips for bores. This inclusion of several standards within one standard and supplemented by technical delivery condi tions and guidelines for fitting has produced a whole and complete standard which can be applied without the inclusion of additional standards. The following explanations are given with respect to this standard, Re Title ‘The term “(retaining rings)" has been added to the title of the standard. The old designation “circlips” has been retained, although these components are used only for the axial retention of components in bores and have no locking action. The organizational problems associated with a general change in designation desirable for the sake of clarity were, because of the wide distribution of these standards, also rated as more important than the danger of misunderstood information on the part of the standards user due to an inappropriate title Re Clause 1 Concept “This clause was included in order to prevent possible errors in the application and function of the parts resulting from the designation, Re Clause 2 Dimension letters, symbols Clause 2 lists and describes the dimension letters and symbols used in the standard.Page 12 DIN 472 Re Clause 3 Dimensions, designation, design data This clause contains the dimensions of the circlips of normal type and heavy type. Required design data have been added. “The dimensions of the circlips or their tolerances have been corrected slightly in a few cases without any danger thereby of replacement difficulties, ‘Two types of circlip have been shown. The second type of circlip shape (included as an additional option has been used for some years. In certain fields it has had manufacturing advantages. The application and function of the circlips do not ifer from the type previously represented in this standard (lefthand illustration). Toleranced dimensions for the shape and position of the bore groove have been included at the request of the users. “These specifications apply to the general application of circlips. Other internal specifications may be used for individual this applies also to the groove surfaces for which no generally valid regulations were able to be given in this standard, ‘The possibility of reducing the number of types of circlips, aso possibly by means of main and subsidiary series for the bore diameters, has been thoroughly examined. But no technically feasible solution was able to be found, since practi- cally all sizes with varying datum points ara in use as a result of the already mentioned wide range of application. It was also not possible to offer a selection according to rolling bearing diameters. Re Clause 4 Material Details of the material have been modified. Three materials have been selected as the most usual from DIN 17 222. Other ‘materials must be agreed by the parties concerned. Re Clause § Finish Details of the finish have been extended and adapted to present conditions. With electroplated circlips, the danger of hydrogen embrittlement is relatively great and requires special attention within the meaning of DIN 267 Part 9. Part ular reference has therefore been made to DIN 267 Part 9. According to this standard, the situation is approximately as follows: In order to avoid hydrogen-induced delayed brittle fractures in the electroplated surface protection of circlips, the galvanic treatment and heat treatment before and after electroplating must be selected so that only a small amount of hydrogen is taken up in the pickling and galvanic treatment and this hydrogen is furthermore driven off again to a large extent, Normally, delayed brittle fractures can be avoided by these measures. If brittle fractures must be avoided with specific, statistical certainty, the taking of appropriate quantities of random samples is recommended followed by fatigue testing of these samples over 48 hours at room temperature; the circlips must thereby be loaded up to the bore diameter dy Re Clause 6 Testing Clause 6 covering the testing of circlips is new to the standard. It specifies tests which are required for the assessment of the mechanical and functional properties of circlips. The contents of this clause results from the experience of manufac: ‘turers and users and correspond to the general applications for circlips. This also applies to the details of accoptance testing given in subclause 6.6. These details are based on DIN 267 Part 5. Special agreements are not thereby excluded Re Clause 7 Load bearing capacity Clause 7 contains details of the calculation of the load-bearing capacities of circlips and indicates how the extended data given in tables 1 and 2 have arisen. These data refer only to normal applications but clause 7 gives the principles for cal- culating the load-bearing capacities also for other applications. Re Clause 8 Shape of groove Various possibilities are presented in clause 8 for the shape of the grooves for circlips and these are also applicable from ‘an economic standpoint. Decisions on appropriate shapes must be made on an individual basis. Re Clause 9 Fitting the circlip Clause 9 recommends the use of cones for fitting circlips. This type of fitting is of particular advantage in bulk manutfae- turing.