Fig. 2. Internal corner clearance
Spline Variations.— The maximum allowable variations for involute splines are listed in Table 4.
花键偏差—花键最大综合偏差值见表4。
Profile Variation: The reference profile, from which variations occur, passes through the point used to determine the actual space width or tooth thickness. This is either the pitch point or the contact point of the standard measuring pins.
齿形偏差：用齿廓上发生偏差的一个点，来定义实际弧齿槽宽或实际弧齿厚。这个点可以是节圆（和齿廓）的交点，也可以是测量针规（和齿廓）的交点。
译注C5：在《ISO 4156-1》中，有图形说明，请参照图形理解。另在《3478.1-2008》表1中有定义。
Profile variation is positive in the direction of the space and negative in the direction of the tooth. Profile variations may occur at any point on the profile for establishing effective fits and are shown in Table 4.
齿形偏差是弧齿槽宽的正方向或者是弧齿厚的反方向。实际装配的时候，齿廓的任何点上都有可能发生偏差。
Lead Variations: The lead tolerance for the total spline length applies also to any portion thereof unless otherwise specified.
齿向偏差：指的是花键全齿长上或者指定长度方向上的偏差。
Out of Roundness: This condition may appear merely as a result of index and profile variations given in Table 4 and requires no further allowance. However, heat treatment and deflection of thin sections may cause out of roundness, which increases index and profile variations. Tolerances for such conditions depend on many variables and are therefore not tabulated. Additional tooth and/or space width tolerance must allow for such conditions.
圆度（偏差）：（理论上）仅仅由于表4中规定的齿距偏差和齿形偏差引起。但是，热处理和薄壁零也会产生圆度（偏差），从而增大齿距偏差和齿形偏差。这种公差大小涉及到多种因素，无法一一指明。弧齿槽宽和弧齿厚必须允许这种变化量。
译注D1：工艺编制时，应着重考虑热处理对弧齿槽宽和弧齿厚的影响。
Eccentricity: Eccentricity of major and minor diameters in relation to the effective diameter of side fit splines should not cause contact beyond the form diameters of the mating splines, even under conditions of maximum effective clearance. This standard does not establish specific tolerances.
偏心距：齿侧配合时，大径和小径配合引起的偏心距离，不得超过构成圆直径范围，特别是在最大作用侧隙时。本标准没有规定（偏心距）的公差值。
Eccentricity of major diameters in relation to the effective diameters of major diameter fit splines should be absorbed within the maximum material limits established by the tolerances on major diameter and effective space width or effective tooth thickness.
大径配合时引起的偏心距，应该在“大径本身和作用弧齿槽宽或弧齿厚”形成
的“最大实体状态”范围内。
译注D2：最大实体含义请查阅相关的形状和位置公差书籍。本段的含义理解为：若偏心距过大，超过了最大实体范围，可能就无法装配。
If the alignment of mating splines is affected by eccentricity of locating surfaces relative to each other and/or the splines, it may be necessary to decrease the effective and actual tooth thickness of the external splines in order to maintain the desired fit condition. This standard does not include allowances for eccentric location. 如果配合花键的同心度，由于受到“相对应的配合表面产生的偏心距”的影响，就有必要减少外花键作用和实际弧齿厚，以保持原有的配合状态。本标准没有规定（偏心距）位置度公差值。
Effect of Spline Variations.— Spline variations can be classified as index variations, profile variations, or lead variations.
花键的作用偏差—可分为：齿距偏差、齿形偏差和齿向偏差。
Index Variations: These variations cause the clearance to vary from one set of mating tooth sides to another. Because the fit depends on the areas with minimum clearance, index variations reduce the effective clearance. 齿距偏差：导致每个齿与齿的配合的间隙都是不同的。最小间隙决定了配合状况，齿距偏差减少了作用侧隙的范围。
译注D3：“Index Variations”在《ISO 4156》中也称为“Pitch Deviation”。
Profile Variations: Positive profile variations affect the fit by reducing effective clearance. Negative profile variations do not affect the fit but reduce the contact area. 齿形偏差：正向的齿形偏差减少了作用侧隙，反向的齿形偏差只减少接触面积不影响装配。
Lead Variations: These variations will cause clearance variations and therefore reduce the effective clearance.
齿向偏差：齿向偏差导致侧隙偏差的改变，从而减少作用侧隙。
Variation Allowance: The effect of individual spline variations on the fit (effective variation) is less than their total, because areas of more than minimum clearance can be altered without changing the fit. The variation allowance is 60 percent of the sum of twice the positive profile variation, the total index variation and the lead variation for the length of engagement. The variation allowances in Table 4 are based on a lead variation for an assumed length of engagement equal to one-half the pitch diameter. Adjustment may be required for a greater length of engagement. 综合公差（允许值）：单个花键对配合的影响（作用偏差）小于它们的总和。在不改变配合的情况下，（由于总和的影响）这些大于最小间隙的接触区域也会发生改变。在配合长度上，综合公差等于“齿形偏差、总齿距偏差和齿向偏差之和”两倍的60%。表4中的值，是按花键配合长度为其节圆直径一半的齿向公差来计算的。若长度不同，必要时可调整λ。
译注D4：关于“Variation Allowance”，在《ISO 4156》中，9.2更为合理和容易理解。本标准中定义的公式与美国米制公式《B92.2M》不同。
Effective and Actual Dimensions.— Although each space of an internal spline may have the same width as each tooth of a perfect mating external spline, the two
may not fit because of variations of index and profile in the internal spline. To allow the perfect external spline to fit in any position, all spaces of the internal spline must then be widened by the amount of interference. The resulting width of these tooth spaces is the actual space width of the internal spline. The effective space width is the tooth thickness of the perfect mating external spline. The same reasoning applied to an external spline that has variations of index and profile when mated with a perfect internal spline leads to the concept of effective tooth thickness, which exceeds the actual tooth thickness by the amount of the effective variation.
由于内花键有误差，所以该外花键即使每个弧齿厚与内花键每个弧齿槽宽想的，也不能装入内花键。若要使理想的外花键在任意位置上都可以装入内花键，且作用侧隙为零，则该内花键所有弧齿槽宽均需按最大干涉量加宽。这些加宽后的弧齿槽宽即是内花键的各实际弧齿槽宽。与之相配的理想外花键的弧齿厚即是内花键的作用弧齿槽宽。反之也应用在外花键上。有齿距误差和齿形误差的外花键，与理想的内花键的弧齿槽宽相配和的弧齿厚，即是作用弧齿厚，作用弧齿厚是由实际弧齿厚按照作用偏差往外扩大得到的。
The effective space width of the internal spline minus the effective tooth thickness of the external spline is the effective clearance and defines the fit of the mating parts. (This statement is strictly true only if high points of mating parts come into contact.) Positive effective clearance represents looseness or backlash. Negative effective clearance represents tightness or interference.
内花键的作用弧齿槽宽减去外花键的作用弧齿厚即为作用侧隙，它决定了配合形式（这一定义只有在配合的极限点是接触的状态下才严格成立）。（相减后）正值的作用侧隙形成松配或间隙配合；负值的作用侧隙形成紧配或过盈配合。
Space Width and Tooth Thickness Limits.— The variation of actual space width and actual tooth thickness within the machining tolerance causes corresponding variations of effective dimensions, so that there are four limit dimensions for each component part.
These variations are shown diagrammatically in Table 5.
弧齿槽宽和弧齿厚的极限—由制造时产生的实际弧齿槽宽和实际弧齿厚，由于各种偏差就产生了作用偏差尺寸。所以对每个配合零件，共有四种极限尺寸。 各种偏差见表5。
Table 5. Specification Guide for Space Width and Tooth Thickness
ANSI B92.1-1970, R1993
译注E1：对于内花键，实际弧齿槽宽大于作用弧齿槽宽；对于外花键，作用弧齿厚大于实际弧齿厚。
译注E2：综合公差和制造公差的值，在后面的计算举例中，是采用查表的方法。在B92.1-1996版本中，可以采用以下公式计算：
Spine Pitche P/PS 2.5/5 and 3/6 4/8 and 5/10 6/12 and 8/16 10/20 and 12/24 16/32 and 20/40 24/48 thru 48/96 64/128 and 80/160 128/256 λ 0.35N+20 0.23N+18 0.20N+15 0.17N+14 0.12N+13 0.12N+11 0.10N+10 0.08N+9 m 0.18N+14 0.15N+13 0.15N+11 0.10N+11 0.07N+11 0.07N+11 0.06N+9 0.05N+9
The minimum effective space width is always basic. The maximum effective tooth thickness is the same as the minimum effective space width except for the major diameter fit. The major diameter fit maximum effective tooth thickness is less than the minimum effective space width by an amount that allows for eccentricity between the effective spline and the major diameter. The permissible variation of the effective clearance is divided between the internal and external splines to arrive at the maximum effective space width and the minimum effective tooth thickness. Limits for the actual space width and actual tooth thickness are constructed from suitable variation allowances.
最小作用弧齿槽宽总是为基本值。除了外径配合形式外，“最大作用弧齿厚”和“最小作用弧齿槽宽”的值相等。外径配合情况，由于齿侧和大径（与各自相配的零件）相配合后存在偏心，这时要求“最大作用弧齿厚”要小于“最小作用弧齿槽宽”。（实际弧齿厚）去掉“作用侧隙”的影响，在内花键上得到“最大作用弧齿槽宽”，在外花键上得到“最小作用弧齿厚”。“实际弧齿槽宽”和“实际弧齿厚”的极限值来源于“综合公差”。
Use of Effective and Actual Dimensions.— Each of the four dimensions for space width and tooth thickness shown in Table 5 has a definite function.
作用和实际尺寸的使用—表5中显示的四个齿槽宽和齿厚，每一个尺寸都特定的作用。
Minimum Effective Space Width and Maximum Effective Tooth Thickness: These dimensions control the minimum effective clearance, and must always be specified. 最小作用弧齿槽宽和最大作用弧齿厚：这些尺寸控制最小作用侧隙，必须指定。
Minimum Actual Space Width and Maximum Actual Tooth Thickness: These dimensions cannot be used for acceptance or rejection of parts. If the actual space width is less than the minimum without causing the effective space width to be undersized, or if the actual tooth thickness is more than the maximum without causing
the effective tooth thickness to be oversized, the effective variation is less than anticipated; such parts are desirable and not defective. The specification of these dimensions as processing reference dimensions is optional. They are also used to analyze undersize effective space width or oversize effective tooth thickness conditions to determine whether or not these conditions are caused by excessive effective variation.
最小实际弧齿槽宽和最大实际弧齿厚：这些尺寸不能用于作为接收或拒收零件的标准。如果实际弧齿槽宽小于最小值，但没有影响最小作用弧齿槽宽，或者如果实际弧齿厚大于最大值，但没有影响到最大作用弧齿厚，这种偏差小于期望值的零件是可用的，不应判定为不合格品。这些尺寸在工艺中仅作为非强制性的参考尺寸。它们也可以用于分析过小作用弧齿槽宽或过大作用弧齿厚的情况，以判定这些情况是否由于超差的作用误差造成的。
Maximum Actual Space Width and Minimum Actual Tooth Thickness: These dimensions control machining tolerance and limit the effective variation. The spread between these dimensions, reduced by the effective variation of the internal and external spline, is the maximum effective clearance. Where the effective variation obtained in machining is appreciably less than the variation allowance, these dimensions must be adjusted in order to maintain the desired fit. 最大实际弧齿槽宽和最小实际弧齿厚：这些尺寸控制加工误差和作用误差的极限。这些尺寸范围，由于内花键和外花键的作用偏差而减少，得到最大的作用侧隙。加工中的作用偏差（值）略小于综合公差时，这些尺寸必须经过适当调整以保证预期的配合。
Maximum Effective Space Width and Minimum Effective Tooth Thickness: These dimensions define the maximum effective clearance but they do not limit the effective variation. They may be used, in addition to the maximum actual space width and minimum actual tooth thickness, to prevent the increase of maximum effective clearance due to reduction of effective variations. The notation “inspection optional” may be added where maximum effective clearance is an assembly requirement, but does not need absolute control. It will indicate, without necessarily adding inspection time and equipment, that the actual space width of the internal spline must be held below the maximum, or the actual tooth thickness of the external spline above the minimum, if machining methods result in less than the allowable variations. Where effective variation needs no control or is controlled by laboratory inspection, these limits may be substituted for maximum actual space width and minimum actual tooth thickness.
最大作用弧齿槽宽和最小作用弧齿厚：这些尺寸定义了最大的作用侧隙，但它们不能限定作用偏差。它们可用作为“最大实际弧齿槽宽”和“最小实际弧齿厚”的附加（检验或控制方式），以防止由于减少作用偏差而引起的“最大作用侧隙”变大（超过最大值）。“非强制的检测”一词可以作为装配要求附加在那些“最大作用侧隙”上， 但不要求完全控制的情况。它的意思是：如果加工方法（产生的偏差）小于综合公差，不增加这些“非强制的检验”，那么“内花键实际弧齿槽宽”必须控制在最大以内，或者“外花键实际弧齿厚”必须控制在最小值以上。如果不要求控制作用偏差或者这个靠实验室检测控制，那么这些限制可以代替“最大实际弧齿槽宽”和“最小作用弧齿厚”。
译注E3：此项检验方法，请参照《GB3478.1-2008》中图6的 检验图解。意思是：内花键，用止规检验“最大实际弧齿宽”，能止住，就表示“最大作用弧齿槽宽”是公差范围内的；外花键，用止规检验最小实际弧齿槽宽，能止住，就表示“最小作用弧齿宽”是公差范围内的。这个前提是加工公差要很小。这个代替检验的原因是实际的弧齿槽宽和弧齿厚难以检验。