Fillet Root Splines are those in which a single fillet in the general form of an arc joins the sides of adjacent teeth.
圆齿根花键：两侧渐开线齿形由一段或近似一段过渡曲线与底部（小圆）相连的花键。
Flat Root Splines are those in which fillets join the arcs of major or minor circles to the tooth sides.
平齿根花键：两侧渐开线齿形各由一段过渡曲线与齿根圆相连接的花键。
Form Circle is the circle which defines the deepest points of involute form control of the tooth profile. This circle along with the tooth tip circle (or start of chamfer circle) determines the limits of tooth profile requiring control. It is located near the major circle on the internal spline and near the minor circle on the external spline.
渐开线构成圆：渐开线构成圆是用于控制齿廓上渐开线的极限距离的圆。渐开线构成圆与齿顶圆（或者倒角线的起点所在的圆）共同构成了“所要求的渐开线齿廓”的范围。渐开线构成圆的位置靠近内花键的大圆（齿根圆）或者外花键的小圆（齿根圆）。
译注B6：在《GB/T 3478.1-2008》中，将Form Circle定义为两个圆：键的渐开线终止圆（内花键用）和渐开线起始圆（外花键用）。而在本标准中，将这两个圆统称为Form Circle，译者将Form Circle翻译为渐开线构成圆。（这个圆与另外一个圆，构成了渐开线使用的范围）。具体看《GB 3478.1》中，表1序号17 -20和图1 渐开线花键联结。
译注B7：定义Form Circle（渐开线构成圆）的原因是：在渐开线构成圆与齿顶圆（或者倒角线的起点所在的圆）之间的花键的齿形必须为渐开线齿形，其余部分不一定按照渐开线成形。
译注B8：句中chamfer，并不是指真正的倒角，而是一种平滑的过渡线。（渐开线和大径或小径的过渡线） 译注B9：这个范围是一个直径的范围。也就是从直径A开始到直径B为止，这中间的齿廓必须为渐开线。
Form Clearance (cF) is the radial depth of involute profile beyond the depth of engagement with the mating part. It allows for looseness between mating splines and for eccentricities between the minor circle (internal), the major circle (external), and their respective pitch circles.
齿形裕度：齿形裕度(cF)是相互配合的内、外花键的渐开线齿廓超过结合部分的径向距离。（定义齿形裕度的原因是）它允许相互配合的内、外花键之间存在一定间隙，而且小径（内花键）、大圆（外花键）、以及内、外花键各自的节圆之间存在一定的偏心距。
译注B10：关于cF请看《GB 3478.1》中，图1 渐开线花键联结cF，或者本标准表6，图中cF。
Form Diameter (DFe, DFi) the diameter of the form circle. 渐开线构成圆直径（DFe, DFi）：渐开线构成圆所在圆的直径。（见译注B4和表6中的图）
Internal Spline is a spline formed on the inner surface of a cylinder. 内花键：在圆柱体的孔的内表面形成的花键。
Involute Spline is one having teeth with involute profiles. 渐开线花键：花键的齿形为渐开线形式的花键。
Lead Variation is the variation of the direction of the spline tooth from its intended direction parallel to the reference axis, also including parallelism and alignment variations (see Fig. 1a). Note: Straight (nonhelical) splines have an infinite lead. 齿向偏差：花键的键齿的实际齿线与花键的参考轴线之间的平行度偏差的最大绝对值。它包括平行度偏差（见图1b）和同轴度偏差（见图1a）。注意：直齿花键（非螺旋花键）的齿向偏差为无限长。
译注B11：在《ISO 4156 Straight cylindrical involute splines —Metric module, side fit》中，“Lead variation”定义为“Helix deviation”。国标《GB 3478.1》定义为“齿向公差”。本人认为《ISO 4156》中的定义和图形更详细和易于理解。根据《ISO 4156》中定义，“Form deviation”(综合形状偏差)，包括了三种：Profile deviation、Index deviation和helix deviation。“Form deviation”的值即为《GB 3478.1》中的“Deviation allowance （λ）”。λ=（Total Profile deviation + Total Index deviation+ Total helix deviation）
Length of Engagement (Lq) is the axial length of contact between mating splines.
配合长度（Lq）：配合长度是配合花键接触段轴向的长度。
Machining Tolerance (m) is the permissible variation in actual space width or actual tooth thickness.
加工公差（m）：加工公差是花键的实际弧齿槽宽和实际弧齿厚的允许的变动量。
译注B12：在 《GB 3478.1》中，加工公差代号为T。
Major Circle is the circle formed by the outermost surface of the spline. It is the outside circle (tooth tip circle) of the external spline or the root circle of the internal spline. 大圆：大圆是花键的最大齿形面的形成的圆。它是外花键的外圆（齿顶圆），和内花键的齿根圆。
Major Diameter (Do, Dri) is the diameter of the major circle. 大径：大圆直径（Do, Dri）是大圆所在圆的直径。
Minor Circle is the circle formed by the innermost surface of the spline. It is the root circle of the external spline or the inside circle (tooth tip circle) of the internal spline.
小圆：小圆是花键的最小齿形面的形成的圆。它是外花键的齿根圆，和内花键的内圆（齿顶圆）。
Minor Diameter (Dre, Di) is the diameter of the minor circle. 小圆直径：小圆直径（Dre, Di）是小圆所在圆的直径。
Nominal Clearance is the actual space width of an internal spline minus the actual tooth thickness of the mating external spline. It does not define the fit between mating members, because of the effect of variations.
理论侧隙：理论侧隙是“内花键的实际弧齿槽宽”减去与之相互配合的“外花键的实际弧齿厚”所得的值。由于（内、外花键）的各种实际偏差，理论侧隙不能用于确定花键的配合情况。
Out of Roundness is the variation of the spline from a true circular configuration. 圆度：圆度是花键与理论圆的轮廓之间的偏差。
Parallelism Variation is the variation of parallelism of a single spline tooth with respect to any other single spline tooth (see Fig. 1b).
平行度偏差：平行度偏差是单根键齿相对其它的单根键齿之间的平行偏差。（见图1b）
Pitch (P/Ps) is a combination number of a one-to-two ratio indicating the spline proportions; the upper or first number is the diametral pitch, the lower or second number is the stub pitch and denotes, as that fractional part of an inch, the basic radial length of engagement, both above and below the pitch circle. 径节（分数制）（P/Ps）：径节（分数制）是一个1比2组合分数，用于表示花键的比率。分数中第一个数（分子）表示的是花键的节圆径节，第二个数（分母）表示的是齿根径节，其中的分数用英寸表示，节圆径节表示的是在节圆上方的键齿在半径方向上的配合长度，齿根径节表示的是在节圆下方的键齿在半径方向上的配合长度。
译注B13：可以理解为节圆将整个花键键齿一分为二，节圆上方的键齿的齿高为径节，节圆下方的键齿的齿高为齿根径节。在实际计算时要考虑到渐开线终止圆与修缘线所在圆对键齿有效结合齿高的影响，并将其扣除。
Pitch Circle is the reference circle from which all transverse spline tooth dimensions are constructed.
节圆：节圆是一个参考圆，花键的所有横向尺寸都是以节圆为基础开始计算的。
译注B14：米制叫分度圆。
Pitch Diameter (D) is the diameter of the pitch circle 节圆直径（D）：节圆直径是节圆所在圆的直径。 .
Pitch Point is the intersection of the spline tooth profile with the pitch circle. 节点：节点是键齿的齿廓与节圆的交点。
Pressure Angle (Φ) is the angle between a line tangent to an involute and a radial line through the point of tangency. Unless otherwise specified, it is the standard pressure angle. 压力角（Φ）：压力角是花键的渐开线齿廓的切线与通过切点的半径所组成的夹角。除非有特殊说明，压力角通常是指标准压力角。
Profile Variation is any variation from the specified tooth profile normal to the flank. 齿形偏差：垂直于侧面的、指定的齿廓（与理论齿廓）的所有公差。
译注B15：见《GB 3478.1-2008》表1中的“齿形公差”定义，本人认为国标从轮廓度检测方面加以解释，应更合理。
Spline is a machine element consisting of integral keys (spline teeth) or keyways (spaces) equally spaced around a circle or portion thereof.
花键：是一种机械零件，它由凸出的齿（花键齿）或凹下的沟（槽）组成，键齿和键槽等分一个完整的圆或圆上部分。
Standard (Main) Pressure Angle (ΦD) is the pressure angle at the specified pitch diameter. 标准压力角（ΦD）（主压力角）：标准压力角是指特定在节圆上的压力角。
Stub Pitch (Ps) is a number used to denote the radial distance from the pitch circle to the major circle of the external spline and from the pitch circle to the minor circle of the internal spline. The stub pitch for splines in this standard is twice the diametral pitch. 齿根径节（Ps）：齿根径节是一个数，它用于表示节圆与外花键的大圆或内花键的小圆之间的半径差。在本标准中，花键的齿根径节是径节的2倍。
Total Index Variation is the greatest difference in any two teeth (adjacent or otherwise) between the actual and the perfect spacing of the tooth profiles.
齿距累计偏差：任意两个齿（相邻齿或其他情况）的实际齿廓与理论值之差的最大值。
Total Tolerance (m + λ) is the machining tolerance plus the variation allowance. 总公差（m +λ）：总公差是加工公差与综合公差之和。
译注B16：在《GB 3478.1》将总公差定义为：T+λ。
Variation Allowance (λ) is the permissible effective variation. 综合公差（λ）：作用偏差(effective variation)的公差值允许范围。
Tooth Proportions.— There are 17 pitches: 2.5/5, 3/6, 4/8,5/10, 6/12, 8/16, 10/20,12/24, 16/32, 20/40, 24/48, 32/64, 40/80, 48/96, 64/128, 80/160, and 128/256. The numerator in this fractional designation is known as the diametral pitch and controls the pitch diameter; the denominator, which is always double the numerator, is known as the stub pitch and controls the tooth depth. For convenience in calculation, only the numerator is used in the formulas given and is designated as P. Diametral pitch, as in gears, means the number of teeth per inch of pitch diameter.
齿比—共有17种齿比：2.5/5，3/6，4/8，5/10，6/12，8/16，10/20，12/24，16/32，20/40，24/48，32/64，40/80，48/96，64/128，80/160和128/256。在这一系列的分数中的分子是（节圆）径节，径节决定了节圆的直径；分数中的分母通常是分子的两倍，分母是齿根径节，齿根径节决定了齿高。为了方便计算，在公式中都使用分子作为计算参数，指定节圆直径，并且与齿轮的表示方式一样定义为径节P尺寸，也就是在节圆上，每英寸长度上的齿数。
译注B17：设计了这17中之外的齿比，本人认为是不合理的。
Table 1 shows the symbols and Table 2 the formulas for basic tooth dimensions of involute spline teeth of various pitches. Basic dimensions are given in Table 3.
表1列出了符号意思，表2列出了各种不同径节的花键公式。表3列出了基本值。
Table 1. American National Standard Involute Spline Symbols
ANSI B92.1-1970, R1993 cv cF D Db Dci Dce DFe DFi Di Do Dre Dri de di Ke Ki L La Lg m Me effective clearance 作用侧隙 form clearance 齿形裕度 pitch diameter 节圆直径 base diameter 基圆直径 pin contact diameter, internal spline 针规触点直径，内花键 pin contact diameter, external spline 针规触点直径，外花键 form diameter, external spline 渐开线起点直径（外花键） form diameter, internal spline 渐开线终点直径（内花键） minor diameter, internal spline 内花键小径 major diameter, external spline 外花键大径 minor diameter, external spline(root) 外花键小径 major diameter, internal spline(root) 内花键大径 外花键用测量针规直径 diameter of measuring pin for internal spline 内花键用测量针规直径 change factor for external spline 外花键变量（见ISO 4156-3） change factor for internal spline 内花键变量（见ISO 4156-3） spline length 花键长度 active spline length 有效花键长度 length of engagement 配合长度 machining tolerance 加工公差 measurement over pins, external 跨棒距 外花键 Mi N P Ps p rf s sv sc ss t tv λ ∈ Φ measurement between pins, internal spline 棒间距 内花键 number of teeth 齿数 diametral pitch 径节 stub pitch 齿根径节 circular pitch 周节 fillet radius 圆角半径 actual space width, circular 实际弧齿槽宽 effective space width, circular 作用弧齿槽宽 allowable compressive stress, psi 允许压缩应力 allowable shear stress, psi 允许剪切应力 actual tooth thickness, circular 实际弧齿厚 effective tooth thickness, circular 作用弧齿厚 variation allowance 综合公差 involute roll angle 渐开线旋转角 pressure angle 压力角 standard pressure angle 标准压力角 内花键针规触点压力角 diameter of measuring pin for external spline ΦD Φci pressure angle at pin contact diameter, internal spline Φce pressure angle at pin contact diameter, external spline 外花键针规触点压力角 Φi pressure angle at pin center, internal spline 内花键针规中心压力角 Φe pressure angle at pin center, external spline 外花键针规中心压力角 渐开线构成圆处压力角 ΦF pressure angle at form diameter 译注B18：PSI这里为应力单位，Pound-Per-Square Inch 磅每平方英寸。
Table 2. Formulas for Involute Spline Basic Dimensions ANSI B92.1-1970, R199 30 deg ΦD Flat Root Side Fit 平齿根齿侧配合 2.5 /5-32 /64 Pitch Stub Pitch 齿根径节 Pitch Diameter节圆直径 Base Diameter基圆直径 Circular Pitch Minimum Effective Space Width最小作用弧齿槽宽 Major Diameter, Internal 内花键大径 Major Diameter, External 外花键大径 Minor Diameter, Internal 内花键小径 Minor 2.5/5 thru 12/24 pitch Dia. Ext. 16/32 pitch and 外花finer 键小10/20 pitch and 径 finer Form Diameter, Internal 内花键终止圆直径 Form Diameter, External 外花键起始圆直径 Form Clearance (Radial) 齿形裕度 37.5 deg ΦD Fillet Root Side Fit 圆齿根齿侧配合 2.5/5-48/96 Pitch 2P N/P D cos ΦD π/P π/(2P ) (N+1.8 )/P (N+1)/ P (N-1)/ P (N-1.8 )/P (N – 2 )/P … (N+1)/P + 2 cF (N– 1)/P– 2 cF Fillet Root Side Fit 圆齿根齿侧配合 2.5/5-48-/96 Pitch 2P N/P D cos ΦD π/P (0.5 π + 0.1 )/P (N+1.6 )/P (N+1)/ P (N-0.8 )/P (N-1.3 )/P (N-1.3 )/P (N-1.3 )/P (N+1)/ P + 2 cF (N-0.8 ) /P – 2cF 45 deg ΦD Fillet Root Side Fit 圆齿根齿侧配合 10/20–128/256 Pitch 2P N/P D cos ΦD π/P (0.5 π + 0.2 )/P (N+1.4 )/P (N+1)/ P (N-0.6 )/P … … (N-1)/ P (N+1)/ P + 2 cF (N– 0.6 )/P–2cF Symbol Term 术语 Flat Root Major Dia Fit 平齿根外径配合 3 /6-16 /32 Pitch 2P N/P D cos ΦD π/P π/(2 P ) (N+1)/ P (N+1)/ P (N-1)/ P (N-1.35 )/P (N-1.35 )/P (N-1.35 )/P (N+0.8)/P–0.004+2cF (N-1)/ P – 2 cF Ps D Db p sv Dri Do Di 2P N/P D cos ΦD π/P π/(2 P ) (N+1.35 )/P (N+1)/ P (N-1)/ P (N-1.35 )/P Dre (N-1.35 )/P (N-1.35 )/P DFi DFe cF (N+1)/P + 2cF (N-1)/P – 2 cF 0.001 D, with max of 0.010, min of 0.002 最大0.01，最小0.002 π = 3.1415927 Note: All spline specification table dimensions in the standard are derived from these basic formulas by application of tolerances. 注：按本表规定的基本公式，应用不同的公差等级，可得到所有其他表中的尺寸。