Designation:F432–04
Standard Specification for
Roof and Rock Bolts and Accessories1
This standard is issued under thefixed designation F432;the number immediately following the designation indicates the year of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.A superscript epsilon(e)indicates an editorial change since the last revision or reapproval.
1.Scope*
1.1This specification covers the chemical,mechanical,and dimensional requirements for roof and rock bolts and accesso-ries.Addressed in this specification are double-end threaded and slotted steel bars;fully grouted bolts and threaded bars; mechanical anchorage devices used for point anchorage appli-cations;roof truss systems;partially grouted deformed bolts; formable anchorage devices;and other frictional anchorage devices.All of these products represent various designs used for ground support systems.This specification can be revised to address new technologies.
1.2The values stated in inch-pound units are to be regarded as the standard.The values given in parentheses are for information only.
1.3This hazard statement applies only to Section10,Test Methods of this specification.This standard does not purport to address the safety concerns,if any,associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
2.Referenced Documents
2.1ASTM Standards:2
A29/A29M Specification for Steel Bars,Carbon and Alloy, Hot-Wrought,General Requirements for
A47/A47M Specification for Ferritic Malleable Iron Cast-ings
A194/A194M Specification for Carbon and Alloy Steel Nuts for Bolts for High-Pressure or High-Temperature Service,or Both
A220Specification for Pearlitic Malleable Iron
A370Test Methods and Definitions for Mechanical Testing of Steel Products
A536Specification for Ductile Iron Castings
A563Specification for Carbon and Alloy Steel Nuts
A568/A568M Specification for Steel,Sheet,Carbon,and High-Strength,Low-Alloy,Hot-Rolled and Cold-Rolled, General Requirements for
A615/A615M Specification for Deformed and Plain Billet-Steel Bars for Concrete Reinforcement
A751Test Methods,Practices,and Terminology for Chemical Analysis of Steel Products
D1248Specification for Polyethylene Plastics Extrusion Materials for Wire Cable
F436Specification for Hardened Steel Washers
F606Test Methods for Determining the Mechanical Prop-erties of Externally and Internally Threaded Fasteners, Washers,and Rivets
2.2ASME Standards:3
B1.1Unified Screw Threads
B1.3M Screw Thread Gaging Systems for Dimensional Acceptability—Inch and Metric Screw Threads
B18.2.2Square and Hex Nuts
3.Terminology
3.1Definitions:
3.1.1bearing plates,plate washers,mine roof plates—plates that serve to distribute the load from the exposed end of the bolt or threaded bar to the rock face or intermediate member.
3.1.1.1header plates—large rectangular bearing plates, usually6in.(152mm)wide by16to18in.(406.4to457.2 mm)long,or any other shape with an equivalent area,used in substitution for wooden header blocks for wider distribution of the bolt load than is possible with standard bearing plates. 3.1.2bendable bolts—bolts furnished with an altered sec-tion at some location,to be specified by the customer,at which the bar will bend.
1This specification is under the jurisdiction of ASTM Committee F16on Fasteners and is the direct responsibility of Subcommittee F16.02on Steel Bolts, Nuts,Rivets,and Washers.
Current edition approved Aug.1,2004.Published August2004.Originally approved in1975.Last previous edition approved in2001as F432–95(2001).
2For referenced ASTM standards,visit the ASTM website,,or contact ASTM Customer Service at For Annual Book of ASTM
Standards volume information,refer to the standard’s Document Summary page on the ASTM website.
3Available from American Society of Mechanical Engineers(ASME),ASME International Headquarters,Three Park Ave.,New York,NY10016-5990.
1
*A Summary of Changes section appears at the end of this standard. Copyright©ASTM International,100Barr Harbor Drive,PO Box C700,West Conshohocken,PA19428-2959,United States.
3.1.2.1Discussion—Bending is necessary to permit instal-lation of bars longer than the mine opening height.This altered section may be produced by hot or cold forging,or by shearing, sawing,trimming,machining,grinding,or a combination of these processes.
3.1.3beveled washers—washers whose faces are at an angle permitting a headed bolt or threaded bar to be installed at a slight angle to the rock face and yet maintained the face of the bolt head perpendicular to the bolt axis.
3.1.4chemical anchors—chemical materials that provide anchorage between the bolt or bar and the drilled hole.
3.1.5expansion shells—anchorage devices that expand to grip the sides of a drilled hole mechanically and transfer load from the location of the anchor to the bar or bolt.
3.1.6extensions—threaded bars used to extend the length of threaded or threaded slotted bars.
3.1.7formable anchorage devices—any roof support de-vices that provide anchorage through some means of physical interference and engagement of the surface of a bar or bolt with any formable material,other than chemical grout,in a bore-hole.
3.1.8frictional anchorage devices—roof support devices that are designed so that the holding force acts over the full contact length.
3.1.9fully grouted bolts and threaded bars—deformed bars or plain bars used with full-length grouting and having special deformations or other design features to provide interlocking between the steel and the grout.
3.1.10hardened washers—washers that have been hard-ened by heat treatment to provide consistency to the torque tension relation necessary to control installation tension of bolts and threaded bars.
3.1.11minimum non-seizure load(MNSL)—the load level in pounds through which bolt/plug thread seizure must not occur.
3.1.12minimum ultimate load(MUL)—the load level in pounds through which bolt/plug thread failure must not occur.
3.1.13rollers,cams—moving devices that,when used with internally threaded cylinders containing external tapered slots, provide expansion to grip the sides of a drilled hole mechani-cally and transfer load from the location of the anchor to the bar or bolt.
3.1.14roof and rock bolts—headed hot-rolled bars with cold-rolled or machine-cut threads at the end,to be used with anchorage devices to hold up mine roofs,hold back walls,or hold down equipment or foundations.
3.1.15roof truss system—a roof support system incorporat-ing bolts that are joined together by crossmember(s)that is (are)tensioned by design.
3.1.16spherical washers or seats—washers that areflat on one side and have a spherical face on the other side.The combination of spherical washer together with a depression in the bearing plate produces a ball-and-socket joint permitting bolts to be installed at a slight angle to the rock face while still maintaining the face of the bolt head perpendicular to the bolt axis.
3.1.17tapered wedges—plain wedges that provide the expansion for threaded slotted bars.
3.1.18tension nuts—nuts that are intended to induce and maintain tension in a bolt.
3.1.19threaded bars—bars that are used with a nut on one end and an anchorage device on the other.They are used in a manner similar to the bolts described in3.1.1
4.
3.1.20threaded couplings—couplings used to permit the assembly of additional externally threaded items.
3.1.21threaded slotted bars—bars threaded at one end each with a forged,burned,or sawed slot at the other,into which a tapered wedge can be inserted.When each assembly is driven into a bottomed hole,the wedge spreads the slot and an anchorage is produced.
3.1.22threaded tapered plugs—threaded wedge that ex-pands the expansion shell by the movement of the threaded plug within the shell as tightening progresses.
4.Ordering Information
4.1Orders for material under this specification shall include at least the following information:
4.1.1Quantity(number of pieces),
4.1.2Name of product together with description of acces-sories,
4.1.3Dimensions,
4.1.4ASTM designation and year of issue,including strength grade,
4.1.5Special requirements,if any,including packaging and thread protection instructions,and
4.1.6Certifications,if required.
4.2The products covered by this specification are currently produced by many manufacturers to a wide variety of designs. It is necessary for the user and the manufacturer to establish the requirements of the individual installation and to agree as to the type of assembly to be employed.See Annex A1and Appendix X1for additional information.
5.Manufacturing Processes
5.1Materials for Bolts,Extensions,and Threaded or Threaded Slotted Bars:
5.1.1Steel shall conform to the requirements shown in Table1and in Specification A29/A29M for plain bars or TABLE1Chemical Requirements
Product Carbon,max,%Sulfur,max,%Phosphorus,max,
%
Heat Product Heat Product Heat Product Bolts,threaded
bars,and threaded
slotted bars A0.750.790.13B0.0500.058 Steel tapered wedges0.800.840.13B0.0500.058 Hardened spherical,
flat,or beveled
washers0.800.840.0500.0580.0500.058 Spherical or beveled
washers0.800.840.0500.0580.0500.058 Bearing and header
plates 1.00 1.040.0500.0580.0500.058 Steel threaded tapered
plugs0.600.640.13B0.0500.058 Steel expansion shells0.300.330.0500.0580.0500.058 A Bars furnished in accordance with Specification A615/A615M may be substituted
for these requirements.
B Check analysis for sulfur if a resulfurized steel is not technically appropriate.
Specification A615/A615M for plain or deformed bars unless otherwise specified.
5.1.1.1Threaded slotted bars may have the slot produced by forging,burning,or sawing.Burned slots of Grades55and75 threaded slotted bars must have the slotted end normalized by heating to a minimum of1600°F(870°C)and air cooling
5.1.1.2Threads on bolts or threaded bars may be cold rolled or machine cut on the hot-rolled bars.
5.2Materials for Tapered Wedges for Use With Threaded Slotted Bars:
5.2.1Malleable iron casting shall conform to Specification A47/A47M.
5.2.2Pearlitic malleable iron castings shall conform to Specification A220,Grades45006or50005.
5.2.3Steel shall conform to the requirements shown in Table1.
5.3Materials for Expansion Shells:
5.3.1Malleable iron castings shall conform to Specification A47/A47M.
5.3.2Steel shall conform to the requirements shown in Table1.
山东师范大学招聘5.3.3Ductile iron castings shall conform to Specification A536,Grades60-40-18.
5.4Materials for threaded tapered plugs used with expan-sion shells shall conform to the test specifications in10.8. 5.5Materials for Bearing and Header Plates,Also Known As Plate Washers or Mine Roof Plates:
5.5.1Steel shall conform to the requirements shown in Table1.
5.5.1.1Bearing and header plates may be strengthened by cold forming or may be hardened by quenching in a liquid medium from above the austenitizing temperature and temper-ing at a temperature of not less than650°F(345°C).
5.6Materials for Spherical,Flat,or Beveled Hardened Washers:
5.6.1Steel shall conform to the requirements shown in Table1.
5.6.1.1Hardened steel washers shall be through hardened by quenching in a liquid medium from above the austenitizing temperature and tempering at a temperature of not less than 650°F(345°C).Case-hardened washers are not permitted. 5.7Materials for Spherical or Beveled Washers:
5.7.1Malleable iron castings shall conform to Specification A47/A47M.
5.7.2Pearlitic malleable iron castings shall conform to Specification A220,Grades45006,50005,or60004.
5.7.3Steel shall conform to the requirements shown in Table1.
5.8Nuts shall be in accordance with Specifications A194/ A194M or A563.Appropriate nuts for each grade of threaded bar are shown in Table2.Higher strength nuts conforming to Specifications A194/A194M or A563may be substituted. When specified on the order or contract,nuts with external dimensions of nominal3⁄4-in.heavy hex or heavy square size may be supplied with5⁄8-in.threads for use with5⁄8-in.threaded bars.
5.9Chemical grouting materials are covered in Annex A3of this specification.
5.10Materials for threaded couplings shall be selected by the manufacturer to ensure compliance with7.6and8.7.
5.11Materials for Bolts and Threaded Bars for Use in Grouted Systems—Plain or deformed steel bars shall conform to Table1or Specification A615/A615M.
5.12Materials for Frictional Anchorage Devices—Sheet steel shall conform to Specification A568/A568M.
5.13Components of roof truss systems shall be manufac-tured in accordance with the appropriate paragraph(s)of Section5of this specification.
5.14Materials for Formable Anchors:
5.14.1Materials for formable anchor tubes are as follows: 5.14.1.1Polyethylenes used for formable anchor tubes shall conform to ASTM D1248Classification Type III,Class A or B,Category5.
N OTE1—All shapes,compositions,and properties of formable anchor materials are not covered by this specification.Users must ensure that the formable anchor material offered is suitable for its intended use.
6.Chemical Composition
6.1Materials used for bolts,threaded bars,threaded slotted bars,spherical,flat,or beveled washers,threaded tapered plugs,tapered wedges,expansion shells,bearing plates and roof truss components shall be as specified in Table1and Section5.
6.2Materials for all cast or wrought metallic items other than those covered in6.1shall conform to the requirements as specified in Section5.
6.3Individual heats of steel or cast iron are not identified in any of thefinished products.
6.4Chemical analyses for steel products shall be performed in accordance with Test Methods,Practices,and Terminology A751.
6.5Materials for formable anchors shall conform to the requirements,if applicable,specified in Section5.
6.6Chemical analyses shall be performed in accordance with Test Methods,Practices,and Terminology A751.
7.Mechanical Properties
7.1Mechanical properties of steel bars,for the manufacture of bolts,threaded bars,or threaded slotted bars shall be as specified in Table3for the required grade.
7.2Mechanical properties of steel bolts,threaded bars,and threaded slotted bars whose slots have been produced without material removal shall be as specified in Table4for the required grade.
7.3Expansion shells,threaded tapered plugs,tapered wedges,and spherical washers shall conform to the applicable specification of Section5and shall successfully perform the required purpose as described in Annex A1.
TABLE2Appropriate Nuts
Bolt,Threaded Bar,or Threaded Slotted
Bar Grade
Nut Specification
30(regular strength)A194,Grade1;A563,Grade B
55(high strength)A194,Grade1;A563,Grade B
75
(extra high strength)A194,Grade2;A563,Grade C
7.4Bearing plates and header plates that are strengthened by quenching and tempering shall have a
maximum hardness of 45HRC.
7.4.1Bearing plates and header plates shall be provided in 10000-lbf (44.5-kN)grade increments.The minimum grade rating permitted shall be 20000lbf (89.0kN).
7.5Hardened washers shall have a hardness range from 35to 45HRC.
7.6Threaded couplings must be capable of developing the actual yield and tensile values of the bolt,threaded bar,or threaded slotted bar with which they are to be used.
7.7Extensions must be in accordance with 7.1and 7.2for the grade of item specified.
7.8Mechanical properties for bolts and threaded bars for use in grouted systems shall be as specified in Table 3for plain bars;and Table 3or Specification A 615/A 615M for deformed bars.Bolts and threaded bars made from plain material must contain some design feature to provide interlocking between the steel and the grout.These items can be supplied threaded or headed.
7.9Threaded slotted bars whose slots have been produced by burning shall be heat treated by normalizing in accordance with 5.1.1.The normalizing heat treatment and the removal of material from the slot,whether it be by burning or sawing,will result in lower test values.When either the burni
ng or sawing or other methods involving metal removal are used,the mechanical properties of threaded slotted bolts shall be as specified in Table 5.
7.10Threaded tapered plugs for expansion anchors must be capable of withstanding the minimum nonseizure load (MNSL)and minimum ultimate load (MUL),in accordance with Table 6.
7.11Tension nuts must be capable of withstanding the ultimate tensile strength of the bolt or rebar of the highest grade with which they are to be used.
7.12The mechanical properties of components of roof truss systems shall be in accordance with the appropriate para-graph(s)of this section.
7.12.1Truss brackets shall be provided in 10000-lbf (44.5-kN)grade increments.
7.13Formable anchor materials shall conform to the appli-cable specifications of Section 5.
8.Dimensions,Mass,and Permissible Variations
8.1Threaded bolts shall conform to the dimensions shown in Fig.1.
8.1.1Deformed bar bolts are bars that have been forged to produce one of the standard heads described in Fig.1.
8.2Threaded and threaded slotted bars shall conform to the dimensions shown in Fig.2.8.3Thread Requirements :
N OTE 2—Thread size variations can be expected due to bar diameter and out-of-round variations.These special requirements reflect practices for external and internal threads that have been found to provide adequate strength and interchangeability.
8.3.1External threads shall be in accordance with ASME B 1.1UNC 1A except that the minimum pitch diameter has been reduced by 0.003in.(0.08mm)and the minimum major diameter has been reduced 0.010in.(0.25mm)to reflect the normal variations expected on hot-rolled bars due to the combined effect of bar diameter and out-of-round tolerances.Information on this increased tolerance is described in Note 3.The modified requirements are listed in Table 7.
N OTE 3—External threads that are to be used with threaded tapered plugs in expansion anchors are permitted to have somewhat increased pitch and major diameter tolerance.As bolt load is increased,the tendency for thread failure through nut diametrical expansion normally increases;howe
ver,in the case of threaded tapered plugs,increased load is accompanied by an increasing compression of the internal threads onto the external threads.This compensation for decreased major diameter is further augmented by the length of engagement which is longer than for standard nuts.Nuts to be used with threaded bars and threaded slotted bars shall be selected to provide adequate strength under these thread condi-tions.
8.3.2Internal threads in threaded tapered plugs and threaded couplings shall be in accordance with ASME B 1.1UNC 1B except that the threads shall be tapped oversize.This oversize is an increase in the pitch diameter of 0.003in.(0.08mm)to allow for handling damage on the external thread and dirt and long engagement in the internal thread.The maximum minor diameters are standard 1B for 11⁄2to 3diameter length of engagement.The modified requirements are listed in Table 7.8.3.3Internal threads in nuts shall be tapped standard UNC 2B size in accordance with ASME.1or may be tapped oversize in accordance with 8.3.2with agreement of producer and purchaser.
8.3.4Gaging of threads shall be performed in accordance with System 21,ASME B 1.3M.Pitch diameter and thread crest diameter limits are specified in Table 7.
8.3.5Threaded tapered plugs shall have a tapped length at least equal to one times the nominal bolt diameter with which they are to be used.
8.3.6Threaded couplings shall have a tapped length at least equal to two times the nominal bolt diameter with which they are to be used.
8.4Round and square hardened washers shall be as shown in Fig.3.
8.4.1There are two types of hardened flat washers avail-able.Type 1is to be furnished unless otherwise specified.8.4.1.1Type 1is either circular or square as shown in Fig.3.It is designed for use with plate washers containing 13⁄8-in.(35-mm)holes,but may be used for all smaller hole sizes.
TABLE 3Mechanical Properties of Steel Bars for the Manufacture of Bolts,Threaded Bars,and Threaded Slotted
Bars AB
Grade
Nominal Diameter,in.C Yield Point min,psi (MPa)Tensile Strength min,
psi (MPa)Elongation 200mm Minimum,
%
惊天霹雳40D 3⁄4–11⁄240000(276)70000(483)12555⁄8
–11⁄255000(379)85000(586)1260D 5⁄8–11⁄260000(414)90000(621)9755⁄8–11⁄275000(517)100000(688)8100
5⁄8
–11⁄2
100000
(689)125000
(862)
6
A Test of bars shall be performed full size.
B
Higher grades would be produced in 20000-psi increments.The minimum tensile strength shall be 25
000psi above the minimum yield strength.The minimum elongation shall be 4%for all grades above 100.C
Actual bar diameters are somewhat less than nominal,especially when roll threading methods are employed.D
Grade 40and 60only apply to deformed bar.
8.4.1.2Type2is the hardenedflat washer in accordance with Specification F436.It may be used only when sufficient clearance is available between the threaded-bar or threaded-rolled-bar body diameter near the head and the washer hole. This washer is not suitable for use with plate washers that contain holes that are more than3⁄8in.(9.5mm)greater in diameter than the nominal bolt diameter.
8.5Bearing and header plates may be of any thickness that successfully meets the test requirements in accordance with 10.4.The maximum hole size for use with bolts up to3⁄4-in. nominal diameter shall
be13⁄8in.(35mm)except that hole size may be11⁄2in.(38mm)when spherical washers or seats are used.Tolerance on hole diameter shall be−0,1⁄8in.(−0,+3.2 mm).Bearing plates for direct bearing applications shall be6 by6in.(152by152mm)with tolerances for length and width of61⁄8in.Larger bearing plates may be furnished,dimensions
TABLE4Load Support Requirements of Steel Bolts,Threaded Bars,(see Annex A2)Threaded Deformed Bars, and Threaded Slotted Bars Whose Slot Has Been Produced Without Metal Removal A
N=Newton
kN=kiloNewton
1lb=4.448N or0.004448kN
Nominal Diameter (in.)/Thread /in.
Thread
Stress Area,
in.2(mm2)
Grade
40B5560B75100 Yield lbs
(kN)C
Ultimate lbs
(kN)C
Yield lbs
(kN)C
Ultimate lbs
(kN)C
Yield lbs
(kN)C
Ultimate lbs
(kN)C
Yield lbs
(kN)C
Ultimate lbs
(kN)C
Yield lbs
(kN)C
Ultimate lbs
(kN)C
5⁄8–110.226
(1.46)D D12400
(55.16)
19200
(85.4)
13600
(60.50)
20300
(90.30)
17000
(75.6)
22600
(100.5)
22600
(100.5)
26300
(130.8)
3⁄4–100.334
(2.65)13400
(59.60)
23400
(104.08)
18400
(81.8)
28400
(126.3)
20000
(89.0)
30100
(133.9)
25100
(111.6)
33400
(148.6)
33400
(146.6)
41800
(193.5)
7⁄8–90.462
(2.96)18500
(82.3)
32300
(143.7)
25400
(113.0)
39300
(174.8)
27700
(123.2)
41600
(185.0)
34700
(154.3)
46200
(205.5)
46200
(205.5)
57800
(267.3)
1–80.606
(3.91)24200
(107.6)
42400
(188.6)
33300
(148.1)
51500
(229.0)
36400
(161.9)
54500
(242.4)
45500
(202.4)
60600
(269.5)
60600
(269.5)
75800
(350.5)
11⁄6–70.763
(4.92)30500
(135.7)
53400
(237.5)
42000
(186.8)
64900
(286.7)
www.ddd13
45800
(203.7)
68700
(305.6)
57200
(254.4)
76300
(339.4)
76300
(339.4)
95400
(441.2)
11⁄4–70.969
(6.25)38800
(172.6)
67800
(301.6)
53300
(237.1)
82400
(366.5)
58100
(258.4)
87200
(387.9)
72700
(323.4)
96900
(431.0)
96900
(431.0)
121100
(560.4)
13⁄8–6 1.155
(7.45)46200
(205.5)
80900
(359.8)
63500
(282.4)
96200
(436.8)
69300
(308.2)
104000
(462.6)
86600
(385.2)
115500
(513.7)
115500
(513.7)
144400
(668.1)
11⁄2–6 1.405
(9.06)56200
(250.0)
98400
(437.7)
77300
(343.8)
119400
(531.1)
84300
(375.0)
126500
(562.7)
105400
(468.8)
140500
(624.9)
140500
(624.9)
175600
(814.6)
A Tests of bolts and threaded bars shall be performed using full-diameter products.
B Information for Gr40and60only applies to deformed bars.
C Required yield and tensile loads shown are calculated by multiplying thread stress areas times the yield point and tensile strength values shown in Table3.Thread stress area is calculated from the mean root and pitch diameters of adrenal threads as follows:
A s50.7854S D20.9743n D2
where:
A s=stress area,in.2
D=nominal diameter,in.,and
n=number of threads per inch.
D5⁄8in.Gr40products are not covered.
TABLE5Load Support Requirements for Threaded Slotted Bars
Whose Slot Has Been Produced by Methods Involving Metal
Removal A
Nominal Diameter, in.Thread Stress
Area,min,in.2
(mm2)ded
Grade55
Yield Load,min,lbf
(kN)B
Ultimate Tensile
Load,min,lbf(kN)B
10.606(3.91)30000(133.3)46400(206.2) 11⁄40.969(6.25)48000(213.4)74200(329.9) 13⁄8 1.155(7.45)57200(254.2)88400(393.1) 11⁄2 1.405(9.06)69600(309.4)107500(478.0) A Tests of bolts,threaded bars,and threaded slotted bars shall be performed using full-diameter products.
B Required yield and tensile loads shown are calculated by multiplying thread stress areas times the yield point and tensile strength values shown in Table2. Thread stress area is calculated from the mean of the mean root and pitch diameters of Class3external threads as follows:1100.la
A s50.7854S D20.9743n D2
where:
A s=stress area,in.2
D=nominal diameter,in.,and
n=number of threads per inch.
TABLE6Plug Grade Rating System
Nominal
Diameter,
in.
Grade1Grade2Grade3Grade4 MNSL A MUL B MNSL A MUL B MNSL A MUL B MNSL A MUL B 1⁄27.014.210.717.013.519.916.322.7 5⁄812.422.617.027.121.531.626.036.1 3⁄418.433.425.1†40.131.746.8†38.453.4†7⁄825.4†46.234.755.440.064.740.073.9 133.360.640.072.740.084.840.096.9 11
⁄840.076.340.091.640.0106.840.0122.0 11⁄440.096.940.0116.340.0135.740.0155.0†13⁄840.0115.5†40.0138.640.0161.740.0184.8 11⁄240.0140.5†40.0168.640.0196.740.0224.8
A MNSL—Minimum Non-Seizure Load(1000lb).
B MUL—Minimum Ultimate Load(1000lb).
†Editorially corrected.
豫公网安备41160202000603
站长QQ:729038198
关于我们
投诉建议