111:. Whereas dial test indicators will give a foreshortened reading if their tips are on an angle to the surface being measured (cosine error), a drawing callout of FIM is defined as referring to the distance traveled by the extremity of the tip—not by the lesser amount that its lever-like action moves the needle. Thus a FIM requirement is only met when the measured part itself is truly in geometric compliance—not merely when the needle sweeps a certain arc of the dial.
87:); or being bent axially (regardless of whether the surfaces are perfectly round and concentric at every cross-sectional point). The purpose of emphasizing the "total" in TIR was to duly maintain the distinction between per-side differences and both-sides-considered differences, which requires perennial conscious attention in
91:
work. For example, all depths of cut in lathe work must account for whether they apply to the radius (that is, per side) or to the diameter (that is, total). Similarly, in shaft-straightening operations, where calibrated amounts of bending force are applied laterally to the shaft, the "total"
64:, or contoured surface of a part, showing its amount of deviation from flatness, roundness (circularity), cylindricity, concentricity with other cylindrical features, or similar conditions. The indicator traditionally would be a dial indicator; today dial-type and digital indicators coexist.
95:
Today TIR in its more inclusive expansion, "total indicator reading", concerns all kinds of features, from round to flat to contoured. One example of how the "total" emphasis can apply to flat surfaces as well as round ones is in the topic of
114:
The "TIR" abbreviation is still more widely known and used than "FIM". This is natural given that (1) many part designs that are still being manufactured are made from decades-old
156:
79:
part such as a shaft to "run out" (verb), that is, to not rotate with perfect smoothness. These conditions include being out-of-round (that is, lacking sufficient
92:
emphasis corresponds to a bend of half that magnitude. If a shaft has 0.1 mm TIR, it is "out of straightness" by half that total, i.e., 0.05 mm.
108:
53:
132:
160:
118:, which still say "TIR"; and (2) generations of machinists were trained with the term "TIR", whereas only recent curriculum uses "FIM".
193:
76:
100:, where both peaks and valleys count toward an assessment of the magnitude of roughness. Statistical methods such as
127:
178:
137:
115:
61:
198:
80:
107:
The newer name "full indicator movement" (FIM) was coined to emphasize the requirement of zero
97:
101:
57:
187:
88:
21:
49:
29:
84:
25:
17:
179:
http://gdtseminars.com/2008/11/17/whats-the-difference-between-tir-and-fim/
72:
71:
and concerned cylindrical or tapered (conical) parts, where "
75:" (noun) refers to any imperfection of form that causes a
104:(RMS) duly address the "total" idea in this respect.
48:), is the difference between the maximum and minimum
83:); eccentricity (that is, lacking sufficient
8:
148:
20:and the fields that it serves (such as
133:Geometric dimensioning and tolerancing
7:
67:The earliest expansion of "TIR" was
14:
40:), also known by the newer name
157:"Total indicator reading (TIR)"
1:
215:
52:, that is, readings of an
128:Flatness (manufacturing)
69:total indicated run-out
42:full indicator movement
34:total indicator reading
194:Mechanical engineering
116:engineering drawings
138:Engineering drawing
98:surface roughness
206:
172:
171:
169:
168:
159:. Archived from
153:
102:root mean square
214:
213:
209:
208:
207:
205:
204:
203:
184:
183:
175:
166:
164:
155:
154:
150:
146:
124:
12:
11:
5:
212:
210:
202:
201:
196:
186:
185:
182:
181:
174:
173:
147:
145:
142:
141:
140:
135:
130:
123:
120:
13:
10:
9:
6:
4:
3:
2:
211:
200:
197:
195:
192:
191:
189:
180:
177:
176:
163:on 2012-07-29
162:
158:
152:
149:
143:
139:
136:
134:
131:
129:
126:
125:
121:
119:
117:
112:
110:
105:
103:
99:
93:
90:
86:
85:concentricity
82:
78:
74:
70:
65:
63:
59:
55:
51:
47:
43:
39:
35:
31:
27:
23:
22:manufacturing
19:
165:. Retrieved
161:the original
151:
113:
109:cosine error
106:
94:
68:
66:
50:measurements
45:
41:
37:
33:
15:
62:cylindrical
30:engineering
188:Categories
167:2011-03-31
144:References
199:Machining
81:roundness
56:, on the
54:indicator
26:machining
18:metrology
122:See also
77:rotating
73:run-out
58:planar
28:, and
89:lathe
46:FIM
38:TIR
32:),
16:In
190::
60:,
24:,
170:.
44:(
36:(
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