AISC-M019L-1994.pdf

MANUAL AISC MOLSL 94 I OF STEEL CONSTRUCTION f eo w P Q FI o- O O , O w ru b w 0- J I O I LOAD they may be galvanized. Type 3 bolts offer improved atmospheric corrosion resistance and weathering characteristics similar to those of ASTM A242 or A588 steels. ASTM A490 bolts are available in diameters from %-in. to 1 %-in. in two types. Type 1 bolts are alloy-steel bolts. Type 3 are alloy-steel bolts with improved atmospheric corrosion resistance and weathering characteristics similar to those of ASTM A242 or A588 steels. ASTM A490 bolts should not be galvanized and caution should be exercised if used in highly corrosive environments. Type 2 (martensite) bolts, popular for many years, have been discontinued. Information on this type can be found in previous editions of the AISC Manual of Steel Construction. When bolts of diameter larger than 1 /2 in. are required, ASTM A449 bolts are permitted to be used for snug-tightened and fully tensioned bearing-type connections; this material is not recognized in LRFD Specification Section A3.3 for use in slip-critical connections nor for use as bolts in diameters not greater than 1% in. ASTM A449 bolts may be galvanized. When an ASTM A449 bolt is used in tension or bearing and is tightened in excess of 50 percent of its minimum specified tensile strength, LRFD Specification Section 53.1 requires that an ASTM F436 washer be installed under the head of the bolt. The nut must be from the approved list in RCSC Specification Section 2(c). Since ASTM A325 nuts and washers for use with high-strength bolts are available only up to l/*-in. diameter, reference should be made to ASTM A563 for nuts and ASTM F436 for washers to select suitable sizes and grades for the intended application. While ASTM A449 seems to be the equal of ASTM A325, there are two important differences which should be noted. First, ASTM A449 bolts are not produced to the same inspection and quality assurance requirements as ASTM A325 bolts. Second, ASTM A449 bolts are not produced to the same heavy-hex head and nut dimensions. Alternative Design Bolts RCSC Specification Section 2d permits the use of other fasteners when they meet the requirements as outlined therein. Figure 8- 1 shows a tension-control or “twist-off bolt which is installed with a special tool which twists off the splined end when the proper , f 0- O r U v) H a Fig. 8-1. Tension-control or “twist-off bolt. AMERICAN INSTITUTE OF STEEL CONSTRLCTION Copyright American Institute of Steel Construction Provided by IHS under license with AISC Licensee=HP Monitoring/1111111164 Not for Resale, 03/05/2009 03:50:00 MSTNo reproduction or networking permitted without license from IHS -,-,- 本文件原文页数较多，文件体积较大，无法上传。 如有需要请发站内信或e m a i l ：l i u y x 866163.c o m 联系人：草庐一苇：w w w .d o c i n .c o m /l i u y x 866 8 - 8 BOLTS, WELDS, AND CONNECTED ELEMENTS 3- Q F 3 O Y N a- Y o- -0 O o- 3 O z U L/) H a I galvanized DH D 1 bolt tension is achieved. Tension-control bolts are commonly available to meet the specifications of ASTM A325 and A490. Compatible Nuts and Washers The compatibility of ASTM A563 nuts and F436 washers with the aforementioned high-strength bolt specifications is as listed in Table 8- 1. Alternatively, appropriate ASTM A194 nuts may be used. RCSC Specification Section 7c gives general requirements for when washers are required for high-strength bolts. Economical Considerations Since the material cost per unit of strength of ASTM A490 bolts is comparable with that of ASTM A325 bolts, it might seem more cost effective to reduce the number of bolts in a given connection by specifying ASTM A490 bolts. However, ASTM A490 bolts are more difficult to tighten and raise inventory and quality control issues associated with the use of multiple fastener grades; mixing of ASTM A325 and A490 bolts of the same diameter should be avoided to assure that the ASTM A490 bolts are installed in the proper location. Thus, the net benefit of specifying ASTM A490 bolts may be less than expected; cost ratios should be considered by the designer. Similarly, cost ratios between grades of alternative design bolts will vary from those of conventional high-strength bolts. Thus, the decision regarding fastener selection will vary accordingly. Regardless of the bolt type selected, the normal sizes of 3/4-in., '/*-in., and 1 -in. diameter are usually preferred. Diameters above one inch are not commonly available, nor are they practical since special tools may be required to achieve fully tensioned installation. Bearing-type connections should be specified whenever possible. Slip-critical connec- tions with coatings other than clean mill scale incur appreciable extra costs associated with blasting, painting, drying, assembling, reblasting, and abrasion touch-up. If slip- critical connections are required for the proper serviceablity of the structure, care should be taken to avoid requiring the faying surfaces to be masked as this also contributes great AMERICAN INSTITUE OF STEEL CONSTRUCTION Copyright American Institute of Steel Construction Provided by IHS under license with AISC Licensee=HP Monitoring/1111111164 Not for Resale, 03/05/2009 03:50:00 MSTNo reproduction or networking permitted without license from IHS -,-,- 本文件原文页数较多，文件体积较大，无法上传。 如有需要请发站内信或e m a i l ：l i u y x 866163.c o m 联系人：草庐一苇：w w w .d o c i n .c o m /l i u y x 866 BOLTED CONSTRUCTION m Ob95925 0009202 bL0 8 - 9 expense; coatings which provide a Class A or Class B slip coefficient may be an economical alternative to masking. Dimensions and Weights ASTM A325 and A490 bolts, A563 nuts, and F436 washers are given identifying marks as illustrated in Figure 8-2. A detailed description of identifying marks may be found in the RCSC Specification. Dimensions of ASTM A325 and A490 bolts, A563 nuts, and F436 washers are given and illustrated in Table 8-2. Threading dimensions of high- strength bolts are given in Table 8-7. Weights of conventional ASTM A325 and A490 bolts, A563 nuts, and F436 washers are given in Table 8-3. For dimensions and weights of tension-control ASTM A325 and A490 bolts, refer to manufacturers literature or IFI. For dimensions and weights of ASTM A449 bolts, refer to Table 8-6. Threads for high-strength bolts may be rolled or cut. Note that thread lengths for high-strength bolts are shorter than those for non-high-strength bolts. This allows the threads to be excluded from the shear plane when the thickness of the connected ply closest to the nut is as shown in Figure 8-3. While the RCSC Specification permits some thread run-out into the shear plane, it is important to provide sufficient thread to avoid jamming the nut into the run-out when tightening the bolt. Inspection controversy will be reduced by recognizing that bolts intentionally have a limited thread length, a manufacturing tolerance, and limited length increments; as with all manufactured items, dimensional tolerances must be considered. The RCSC Specification recognizes these tolerances in two ways. First, additional washers are permitted to be used under the nut or under the head when circumstances permit. Second, there is no specified bolt “stick-through” requirement since only full- thread engagement of the nut is required; from RCSC Specification Section 2(b), “. . .The length of bolts shall be such that the end of the bolt will be flush with or outside the face of the nut when properly installed.” Arequirement for “stick-through”, sometimes written in project specifications, increases the risk of jamming the nut on the thread run-out, and thus, of preventing tightening. A “stick-through” requirement will not enhance the performance of the bolt and should not be included in a project specification. Alternatively, ASTM A325 bolts with length less than or equal to four times the nominal diameter may be ordered as fully threaded with the designation ASTM A325 T. Fully threaded ASTM A325 T bolts are not for use in bearing-type X connections since it would be impossible to exclude the threads from the shear plane. While this supple- mentary provision exists for ASTM A325 bolts, there is no similar supplementary provision made in ASTM A490 for full-length threading. The ordered length of ASTM A325 and A490 bolts should be calculated as the grip (see Figure 8-2) plus the thickness of the washer(s) plus the allowance from Table 8-2. A thickness of Y32-in. for circular washers and %-in. for beveled washers should be provided per washer used; refer to the RCSC Specification for washer requirements. This total should be rounded to the next higher one-quarter inch. Note that bolts longer than five inches are generally available only in V2-in. increments, except by special arrange- ment with the manufacturer or vendor. While longer lengths may be ordered, an %in. length is generally the maximum stock length available. Clipped washers are available for use in areas of tight clearance. O r= U l . 4 H a AMERICAN INSTITUTE OF STEEL CONSTRUCTION Copyright American Institute of Steel Construction Provided by IHS under license with AISC Licensee=HP Monitoring/1111111164 Not for Resale, 03/05/2009 03:50:00 MSTNo reproduction or networking permitted without license from IHS -,-,- 本文件原文页数较多，文件体积较大，无法上传。 如有需要请发站内信或e m a i l ：l i u y x 866163.c o m 联系人：草庐一苇：w w w .d o c i n .c o m /l i u y x 866 8 - 10 Q=T b BOLTS, WELDS, AND CONNECTED ELEMENTS a I cc U) Y m O lu r O O O Y lu r U) r 9 O I 3 0- . - I r O U M H a 5 h - P, Q I 5 * 5 P h' g- . o C g rq-rl2.zLr( AMERICAN INSTI1 UTE Ob STEEL CONSTRUCTION Copyright American Institute of Steel Construction Provided by IHS under license with AISC Licensee=HP Monitoring/1111111164 Not for Resale, 03/05/2009 03:50:00 MSTNo reproduction or networking permitted without license from IHS -,-,- 本文件原文页数较多，文件体积较大，无法上传。 如有需要请发站内信或e m a i l ：l i u y x 866163.c o m 联系人：草庐一苇：w w w .d o c i n .c o m /l i u y x 866 BOLTED CONSTRUCTION Ob95925 0009204 493 = *-l1 Table 8-2. Dimensions of High-Strength Fasteners, in. 1. D. L Taper in Thickness 2:12 2:12 2:12 2:12 2:12 2:12 2:12 2:12 2:12 Min. Edge Distance d 7/16 9 2 1 1 2 5 1 7 / 8 i 13/s2 I7/s2 1% ilerances as specified in ASTM A325 and A490. ilerances as specified in ASTM A.563. STM F436 Washer Tolerances, in Nominal Outside Diameter -1132; +1/32 Flatness: ma. deviation from straight-edge placed on cut side shall not exceed 0.010 Concentricity: center of hole to outside diameter (full indicator runout) 0.030 Burr shall not project above immediately adjacent washer surface more than 0.010 For use with American standard beams (S) and channels (C). Tabular value does not include thickness of washer(s). Nominal Diameter of Hole -O; +1/32 i For clipped washers only. ? AMERICAN INSTITUTE OF STEEL CONSTRUCTION Copyright American Institute of Steel Construction Provided by IHS under license with AISC Licensee=HP Monitoring/1111111164 Not for Resale, 03/05/2009 03:50:00 MSTNo reproduction or networking permitted without license from IHS -,-,- 本文件原文页数较多，文件体积较大，无法上传。 如有需要请发站内信或e m a i l ：l i u y x 866163.c o m 联系人：草庐一苇：w w w .d o c i n .c o m /l i u y x 866 8 - 12 BOLTS, WELDS, AND CONNECTED ELEMENTS Table 8-3. Weights of High-Strength Fasteners, pounds per 100 count - 1 /2 - - - - 333 344 355 366 379 - 3 / 4 47.0 49.6 52.2 55.3 58.4 61.6 64.7 67.8 lomina 7 h 74.4 78.0 81.9 86.1 90.3 94.6 98.8 _ _ - bolt Di 1 104 1 o9 114 119 124 130 135 - eter, ¡i 1 i/s _ _ - - 148 1 54 160 167 174 181 - 5 h 29.4 31.1 33.1 35.3 37.4 39.8 41.7 43.9 46.1 48.2 50.4 52.5 54.7 56.9 59.0 61.2 - 1 /4 - - 197 205 212 220 229 237 - 1 3/s - - - 261 270 279 290 300 - 20.5 21.9 23.3 24.7 26.1 27.4 28.8 3% 30.2 70.9 74.0 77.1 80.2 83.3 86.4 89.5 92.7 103 107 111 116 120 124 128 133 - 141 146 151 157 162 168 173 179 184 190 196 201 - _ 188 195 202 209 21 6 223 230 237 244 251 258 265 246 255 263 272 280 289 298 306 315 324 332 341 _ 31 O 321 332 342 353 363 374 384 395 405 41 6 426 _ 39 1 403 416 428 441 453 465 478 490 503 515 527 44 34.3 4/2 35.7 4 3 / 4 37.1 5v4 39.9 5 38.5 5% 41.2 5 3 / 4 42.6 6 44.0 6l/4 - Si/, - 63/4 - 7/4 - 7v2 - 7 3 / 4 - - 7 63.3 65.5 67.7 69.8 71.9 74.1 76.3 78.5 80.6 82.8 84.9 87.1 89.2 - - - - - - 95.8 98.9 102 105 108 111 114 118 121 124 127 130 133 - - - - - - 137 141 146 1 50 1 54 158 163 167 171 175 179 183 187 192 196 - - - 207 212 218 223 229 234 240 246 251 257 262 - - 272 279 286 293 300 307 314 32 1 328 335 342 - - 349 358 367 375 384 392 401 41 O 41 8 427 435 444 _ 437 447 458 468 479 489 500 510 52 1 53 1 542 552 _ 540 552 565 577 589 602 614 626 639 651 664 676 689 _ - 9 I- - 453 - 34.4 13.8 - 563 8.6 3.6 - 12.4 4.8 - 16.9 7.0 - 22.1 9.4 - 28.0 11.3 - 42.5 16.8 - 49.7 20.0 - 100, F436 Circular Washers I 2.1 100, F436 Square 1 23,1 Washers 22.4 - 21 .o - 20.2 - 19.2 - 34.0 - 31.6 - 31.2 - 32.9 - his table conforms to weight standards adopted by the Industrial Fasteners Institute (IFI), updated for washer veights. Entering and Tightening Clearances The assembly of high-strength bolted connections requires clearance for entering and tightening the bolts with an impact wrench. The clearance requirements for conventional high-strength bolts are as given in Table 8-4. When high-strength tension-control bolts are specified, the entering and tightening clearances are as specified in Table 8-5. Snug- Tightened and Fully Tensioned Installation When subjected to shear only, high-strength bolts may be used in snug-tightened bearing-type, fully tensioned bearing-type, and slip-critical connections. When subjected AMERICAN INSTITUTE OF STEEL CONSTRUCTION Copyright American Institute of Steel Construction Provided by IHS under license with AISC Licensee=HP Monitoring/1111111164 Not for Resale, 03/05/2009 03:50:00 MSTNo reproduction or networking permitted without license from IHS -,-,- 本文件原文页数较多，文件体积较大，无法上传。 如有需要请发站内信或e m a i l ：l i u y x 866163.c o m 联系人：草庐一苇：w w w .d o c i n .c o m /l i u y x 866 BOLTED CONSTRUCTION W 0695925 0009206 266 W 8 - 1 3 Table 8-4. Entering and Tightening Clearances, in. Conventional ASTM A325 and A490 Bolts Aligned Bolts h U VI H a Circular I clipped Staggered Bolts 1 Stagger f, in. I Nominal Bolt Diamet 1 2% 25h6 2'/4 23h6 2'/8 1 7/8 1 314 1 5/8 1 ' / 2 1 3/8 1 3/1 6 2 - % r i 33/8 1 5/8 1 ' / 2 1 '14 '546 Hi = height of head, in fi= maximum shank extension,* in Ci = clearance for tightening, in. C2= clearance for entering, in. C3= clearance for fillet,' in. P = bolt stagger, in. F = clearance for tightening staggered bolts, in. 'Based on one standard hardened washer. AMERICAN INSTITUTE OF STEEL CONSTRUCTION Copyright American Institute of Steel Construction Provided by IHS under license with AISC