> 6 to 10 > 10 to 18 > 18 to 30 > 30 to 50 > 50 to 80 > 80 to 120 > 120 to 180 > 180 to 250 > 250 to 315 > 315 to 400 > 400 to 500 > 500 to 630 > 630 to 800 > 800 to 1000 0.069 0.087 0.113 0.139 0.173 0.208 0.251 0.294 0.329 0.364 0.398 0.45 0.502 0.554 0.052 0.065 0.085 0.104 0.13 0.156 0.189 0.222 0.248 0.274 0.3 0.339 0.378 0.417 0.04 0.05 0.065 0.08 0.1 0.12 0.145 0.17 0.19 0.21 0.23 0.26 0.29 0.32 0.043 0.055 0.069 0.087 0.104 0.125 0.147 0.173 0.191 0.217 0.234 0.251 0.277 0.294 0.033 0.042 0.052 0.065 0.078 0.094 0.111 0.13 0.143 0.163 0.176 0.189 0.209 0.222 0.025 0.032 0.04 0.05 0.06 0.072 0.085 0.1 0.11 0.125 0.135 0.145 0.16 0.17 0.023 0.028 0.035 0.043 0.052 0.062 0.074 0.087 0.097 0.107 0.118 0.132 0.139 0.149 0.017 0.021 0.026 0.033 0.039 0.047 0.056 0.065 0.073 0.081 0.089 0.099 0.104 0.112 0.013 0.016 0.02 0.025 0.03 0.036 0.043 0.05 0.056 0.062 0.068 0.076 0.08 0.086 0 0 0 0 0 0 0 0 0 0 0 0 0 0 These values are used with the applicable formulas in Table 13.

Machining Tolerance: A value for machining tolerance may be obtained by subtracting the effective variation, λ, from the total tolerance (T + λ). Design requirements or specific processes used in spline manufacture may require a different amount of machining tolerance in relation to the total tolerance.

Fig. 6a. Profile of Basic Rack for 30° Flat Root Spline

Fig. 6b. Profile of Basic Rack for 30° Fillet Root Spline

Fig. 6c. Profile of Basic Rack for 37.5° Fillet Root Spline

Fig. 6d. Profile of Basic Rack for 45° Fillet Root Spline

British Standard Straight Splines.— British Standard BS 2059:1953, “Straight-sided Splines and Serrations”, was introduced because of the widespread development and use of splines and because of the increasing use of involute splines it was necessary to provide a separate standard for straight-sided splines. BS 2059 was prepared on the hole basis, the hole being the constant member, and provide for different fits to be obtained by varying the size of the splined or serrated shaft. Part 1 of the standard deals with 6 splines only, irrespective of the shaft diameter, with two depths termed shallow and deep. The splines are bottom fitting with top clearance. The standard contains three different grades of fit, based on the principle of variations in the diameter of the shaft at the root of the splines, in conjunction with variations in the widths of the splines themselves. Fit 1 represents the condition of closest fit and is designed for minimum backlash. Fit 2 has a positive allowance and is designed for ease of assembly, and Fit 3 has a larger positive allowance for applications that can accept such clearances.