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size range(in.)			Class RC7 Free Running Fit				Class RC8 Loose Running Fit				Class RC9 Loose Running Fit
				(H9d8)				(H10c9)				(H9b10)
size range(in.)			hole tol. H9	minimum		shaft tol. d9	hole tol. H10	minimum		shaft tol. c9	hole tol. H9	minimum	shaft tol. b1-
			(-0.0000)	clearance		(+0.0000)	(-0.0000)	clearance		(+0.0000)	(-0.0000)	clearance	(+0.0000)
0.0 - 0.12			+0.0010	0.0010		-0.0006	+0.0016	0.0025		-0.0010	-0.0010	0.0040	-0.0016
0.12	- 0.24		+0.0012	0.0012		-0.0007	+0.0018	0.0028		-0.0012	-0.0012	0.0045	-0.0018
0.24	- 0.40		+0.0014	0.0016		-0.0009	+0.0022	0.0030		-0.0014	-0.0014	0.0050	-0.0022
0.40	- 0.71		+0.0016	0.0020		-0.0010	+0.0028	0.0035		-0.0016	-0.0016	0.0060	-0.0028
0.71	- 1.19		+0.0020	0.0025		-0.0012	+0.0035	0.0045		-0.0020	-0.0020	0.0070	-0.0035
1.19	- 1.97		+0.0025	0.0030		-0.0016	+0.0040	0.0050		-0.0025	-0.0025	0.0080	-0.0040
1.97	- 3.15		+0.0030	0.0040		-0.0018	+0.0045	0.0060		-0.0030	-0.0030	0.0090	-0.0045
3.15	- 4.73		+0.0035	0.0050		-0.0022	+0.0050	0.0070		-0.0035	-0.0035	0.010	-0.005
4.73	- 7.09		+0.0040	0.0060		-0.0025	+0.0060	0.0080		-0.0040	-0.0040	0.012	-0.005
7.09	- 9.85		+0.0045	0.0070		-0.0028	+0.0070	0.0100		-0.0045	-0.0045	0.015	-0.007
9.85	- 12.41		+0.0050	0.0080		-0.0030	+0.008	0.012		-0.005	-0.005	0.018	-0.008
12.41		- 15.75	+0.0060	0.010		-0.0035	+0.009	0.014		-0.006	-0.006	0.022	-0.009
15.75		- 19.69	+0.006	0.012		-0.004	+0.010	0.016		-0.006	-0.006	0.025	-0.010
19.69		- 30.09	+0.008	0.016		-0.005	+0.012	0.020		-0.008	-0.008	0.030	-0.012
30.09		- 35.47	+0.0010	0.020		-0.006	+0.016	0.025		-0.010	-0.010	0.040	-0.016
			Hole H8			shaft c9	Hole H10			shaft c10	Hole H10		b10
35.47		- 41.49	+0.006	0.020		-0.010	+0.010	0.025		-0.016	-0.016	0.040	-0.025
41.49		- 56.19	+0.008	0.025		-0.012	+0.012	0.030		-0.020	-0.020	0.050	-0.030
56.19		- 76.39	+0.010	0.030		-0.016	+0.016	0.040		-0.025	-0.025	0.060	-0.040
76.39		- 100.9	+0.012	0.040		-0.020	+0.020	0.050		-0.030	-0.030	0.080	-0.050
100.9		- 131.9	+0.016	0.050		-0.025	+0.025	0.060		-0.040	-0.040	0.100	-0.060
131.9		- 171.9	+0.020	0.060		-0.030	+0.030	0.080		-0.050	-0.050	0.130	-0.080
171.9		- 200	+0.025	0.080		-0.040	+0.040	0.100		-0.060	-0.060	0.150	-0.100

36.5 THE I.S.O. SYSTEM

•Basic features of this system were,

-several diameter steps

-22 holes and 22 shafts

-16 tolerance grades

36.6 PRACTICE PROBLEMS

1. On a ferris wheel we have a 3.5” running journal that is to be pressure lubricated. The fit

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selected for this application is RC4. Use a tolerance diagram to determine the tolerances required on a final drawing. Sketch the hole, and shaft using appropriate drafting techniques.

2. Do complete drawings for a 3.000” hole shaft pair if they have a RC3 fit.

37.Clearance fits are found in,

a)fitted assembly.

b)interchangeable assembly.

c)selective assembly.

d)all of the above.

38.Which statement is more true?

a)production errors cause tolerances.

b)there are no standard tolerances.

c)both a) and b) are completely true.

d)neither a) or b) is true.

39.Given the diagram below, what will the average interference/clearance be?

a)0.008”

b)0.020”

c)0.032”

d)none of the above

3.016”

3.000”

2.992”

2.984”

40.Briefly describe the relationship between tolerance and accuracy. (2%)

41.A hole shaft pair uses a bushing. We know that the fit between the shaft and bushing is LC5, with a nominal diameter of 7” and the fit between the bushing and outer hole is 8” with an FN3 fit. (8%)

a)Draw the tolerance diagrams.

b)Draw the final parts with dimensions and tolerances.

c)What will the gap between the shaft and the bushing be?