Combinations of Involute Spline Types.— Flat root side fit internal splines may be used with fillet root external splines where the larger radius is desired on the external spline for control of stress concentrations. This combination of fits may also be permitted as a design option by specifying for the minimum root diameter of the external, the value of the minimum root diameter of the fillet root external spline and noting this as “optional root.”
渐开线花键种类的混合使用—当外花键需要控制应力集中，而采用大的圆角半径时，平齿根齿侧配合的内花键和圆齿根外花键可以混合使用。这种配合也可指定在外花键的最小齿根圆直径，这个值标明是一个“可选值”。
A design option may also be permitted to provide either flat root internal or fillet root internal by specifying for the maximum major diameter, the value of the maximum major diameter of the fillet root internal spline and noting this as “optional root.”
还有一种允许的设计选择是，指定内花键平齿根或者是内花键圆齿根的最大值，也是“可选值”。
Interchangeability.— Splines made to this standard may interchange with splines made to older standards. Exceptions are listed below. 互换性。－按本标准制造的花键与按旧标准制造的花键具有互换性。例外情况如下。
External Splines: These external splines will mate with older internal splines as follows:
外花键：这些外花键与老旧标准内花键相配情况如下：
Year年代 1946 1950b 1950C 1957 SAE 1960 Major Dia.Fit Flat Root Side Fit Fillet Root Side Fit 外径配合 平齿根齿侧配合 圆齿根齿侧配合 可以 不可以（A）a 不可以（A） 可以（B） 可以（B） 可以（C） 可以（B） 不可以（A） 可以（C） 可以 不可以（A） 可以（C） 可以 不可以（A） 可以（C） a For exceptions A, B, C, see the paragraph on Exceptions that follows. 对于ABC例外情况见
后面解释。
b Full dedendum. 全齿根 c Short dedendum. 短齿根
Internal Splines: These will mate with older external splines as follows: 内花键：这些花键按如下情况与旧标准外花键相配情况如下：
Major Dia.Fit Flat Root Side Fit Fillet Root Side Fit Year年代 外径配合 平齿根齿侧配合 圆齿根齿侧配合 1946 不可以（D）a 不可以（E） 不可以（D） 1950 可以（F） 可以 可以（C） 1957 SAE 可以（G） 可以 可以 1960 可以（G） 可以 可以 a For exceptions C, D, E, F, G, see the paragraph on Exceptions that follows. 对于 C、D、E、F、G，见下后面解释。
Table6.Spline Terms, Symbols, and Drawing Data, 30-Degree Pressure Angle, Flat
Root Side Fit ANSI B92.1-1970, R1993 30-Deg Pressure Angle The fit shown is used in restricted areas (as with tubular parts with wall thickness too small to permit use of fillet roots, and to allow hobbing closer to shoulders, etc.) and for economy (when hobbing, shaping, etc., and using shorter broaches for the internal member). 图中表示只适用限定的范围（比如不允许圆角的管状壁厚，或者滚铣接近基体等），也更经济。 Press fits are not tabulated because their design depends on the degree of tightness desired and must allow for such factors as the shape of the blank, wall thickness, material, hardness, thermal expansion, etc. Close tolerances or selective size grouping may be required to limit fit variations. 过盈配合未列出，因为设计要根据紧配的角度、毛坯形状、壁厚、材料硬度、热膨胀等个因素。应才用最接近或者标准化的尺寸用于限制配合偏差。 Drawing Data 图纸参数 Internal Involute Spline Data External Involute Spline Data Flat Root Side Fit Number of Teeth xx Pitch xx/xx Pressure Angle 30° Base Diameter x.xxxxxx Ref Pitch Diameter x.xxxxxx Ref Major Diameter x.xxx max Form Diameter x.xxx Minor Diameter x.xxx/x.xxx Circular Space Width Max Actual x.xxxx Min Effective x.xxxx The following information may be added as required: Max Measurement Between Pins x.xxx Ref Pin Diameter x.xxxx Flat Root Side Fit Number of Teeth xx Pitch xx/xx Pressure Angle 30° Base Diameter x.xxxxxx Ref Pitch Diameter x.xxxxxx Ref Major Diameter x.xxx/x.xxx Form Diameter x.xxx Minor Diameter x.xxx min Circular Tooth Thickness Max Effective x.xxxx Min Actual x.xxxx The following information may be added as required: Min Measurement Over Pins x.xxxx Ref Pin Diameter x.xxxx The above drawing data are required for the spline specifications. The standard system is shown; for alternate systems, see Table 5. Number of x's indicates number of decimal places normally used.
上表的参数是花键必须指定的。不同（使用）情况见表5。表中x.x表示小数位数。
Exceptions:
a) The external major diameter, unless chamfered or reduced, may interfere with the internal form diameter on flat root side fit splines. Internal splines made to the 1957 and 1960 standards had the same dimensions as shown for the major diameter fit splines in this standard. 除非倒角或减小尺寸，外花键大径可能与平根齿侧配合内花键在“渐开线构成圆”处产生干涉。按1957和1960版制造的外径配合的内花键，与本标准尺寸相同。 b) For 15 teeth or less, the minor diameter of the internal spline, unless chamfered, will interfere with the form diameter of the external spline.
小于或等于15齿的内花键小径，除非倒角，否则可能和外花键的渐开线构成圆产生干涉。
c) For 9 teeth or less, the minor diameter of the internal spline, unless chamfered, will interfere with form diameter of the external spline.
小于或等于9齿的内花键小径，除非倒角，否则可能和外花键的渐开线构成圆产生干涉。
d) The internal minor diameter, unless chamfered, will interfere with the external form diameter.
除非倒角，内花键的小径将与外花键的渐开线构成圆产生干涉。
e) The internal minor diameter, unless chamfered, will interfere with the external form diameter.
除非倒角，内花键的小径将与外花键的渐开线构成圆产生干涉。
f) For 10 teeth or less, the minimum chamfer on the major diameter of the external spline may not clear the internal form diameter.
小于或等于10齿的外花键大径的最小倒角尺寸应保证不可以超过内花键渐开线构成圆。
g) Depending upon the pitch of the spline, the minimum chamfer on the major
diameter may not clear the internal form diameter.
G） 依据花键的径节，大径的最小倒角不可以超过内花键的渐开线构成圆。
Drawing Data.— It is important that uniform specifications be used to show complete information on detail drawings of splines. Much misunderstanding will be avoided by following the suggested arrangement of dimensions and data as given in Table 6. The number of x's indicates the number of decimal places normally used. With this tabulated type of spline specifications, it is usually not necessary to show a graphic illustration of the spline teeth.
图纸参数－统一规范花键图面上的完整信息是很重要的。按表6中给出的推荐的参数（在图纸上列表）可以避免很多误解。X的数量表示小数常用的位数。利用表中花键规范，一般不再需要再示例一个花键齿的图形。
Spline Data and Reference Dimensions.— Spline data are used for engineering and manufacturing purposes. Pitch and pressure angle are not subject to individual inspection. As used in this standard, reference is an added notation or modifier to a dimension, specification, or note when that dimension, specification, or note is: 花键参数和参考尺寸。－花键参数用于工程和制造。径节和压力角不可以单独检测。本标准中，参考尺寸是一个增加的符号或修改的尺寸、规范或注解，如下： 1) Repeated for drawing clarification. 使图纸更清晰明确地表示。
2) Needed to define a nonfeature datum or basis from which a form or feature is generated.
需要为形状或特征的生成而定义一个非特征基准面或基准（系）。
3) Needed to define a nonfeature dimension from which other specifications or dimensions are developed.
需要为其它规范或尺寸的衍生而定义一个非特征尺寸
4) Needed to define a nonfeature dimension at which toleranced sizes of a feature are specified.
需要为指定特征的公差而定义一个非特征尺寸
5) Needed to define a nonfeature dimension from which control tolerances or sizes are developed or added as useful information.
需要为延伸或额外的尺寸或公差控制而定义一个非特征尺寸
Any dimension, specification, or note that is noted “REF” should not be used as a criterion for part acceptance or rejection. 任何标明为“参考”的尺寸、规范或注解都不应当作为零件接收或拒收的标准。
Estimating Key and Spline Sizes and Lengths.— Fig. 3 may be used to estimate the size of American Standard involute splines required to transmit a given torque. It also may be used to find the outside diameter of shafts used with single keys. After the size of the shaft is found, the proportions of the key can be determined from Table 1 on page 2385.
估计齿、花键大小和长度－图3可以估计在一个给定传递扭矩的条件下，美国标准渐开线花键的尺寸。它也可以用于估计带单键的轴的外径。在确定轴的尺寸后，键槽的比例可以在2385页（原件）中的表1确定。
译注F1：一般在图纸中还应标明公差。
Curve A is for flexible splines with teeth hardened to Rockwell C 55–65. For these splines, lengths are generally made equal to or somewhat greater than the pitch diameter for diameters below 11?4 inches; on larger diameters, the length is generally one-third to two-thirds the pitch diameter. Curve A also applies for a single key used as a fixed coupling, the length of the key being one to one and one-quarter times the shaft diameter. The stress in the shaft, neglecting stress concentration at the keyway, is about 7500 pounds per square inch. See also Effect of Keyways on Shaft Strength starting on page 302.
曲线A是用于花键齿硬度为HRC55~65 柔性花键。对于直径低于1.25英寸的花键，这些 花键的键的长度一般制成等于或略大于节圆直径；对于大直径的花键，花键长度一般为节圆直径的 1/3 到2/3。曲线 A 也可以用于一个固定联轴器的单键。键的长度是轴径的1到1 1/4倍。轴上的压力，不考虑键槽处的应力集中，大约为7500磅每平方英寸。可见从302页（原件）开始“键槽对轴强度的影响”。
Curve B represents high-capacity single keys used as fixed couplings for stresses of 9500 pounds per square inch, neglecting stress concentration. Key-length is one to one and one- quarter times shaft diameter and both shaft and key are of moderately hard heat-treated steel. This type of connection is commonly used to key commercial flexible couplings to motor or generator shafts.
曲线 B 代表使用于固定联轴器，应力为 9500 磅每平方英寸的高强度单键，不考虑应力集中。键的长度是轴径的1到1 1/4倍。轴和键都是中等硬度热处理钢。这种连接形式一般用于商用柔性联轴器与电机或与发电机的轴连接。
Curve C is for multiple-key fixed splines with lengths of three-quarters to one and one- quarter times pitch diameter and shaft hardness of 200–300 BHN.
曲线 C 用于长度为节圆直径为 3/4 到 1 1/4，轴硬度为200－300HB的多键固定花键。
Curve D is for high-capacity splines with lengths one-half to one times the pitch diameter. Hardnesses up to Rockwell C 58 are common and in aircraft applications the shaft is generally hollow to reduce weight.
曲线 D 用于长度为1/2 到1倍节圆直径的高强度花键。硬度一般为HRC58，在航空应用中，轴一般为中空以减少重量。
Curve E represents a solid shaft with 65,000 pounds per square inch shear stress. For hollow shafts with inside diameter equal to three-quarters of the outside diameter the shear stress would be 95,000 pounds per square inch. 曲线E代表剪切应力为65000 磅每平方英寸的实心轴。对于内径为外径3/4的空心轴，剪切应力为95000磅每平方英寸。