Hardness
Conversions for Industrial Fasteners
Data for industrial bolts, machine screws and industrial fasteners from Elgin Fastener Group includes hardness conversions. The chart below shows a conversion between Brinell and Rockwell hardness numbers, as well as tensile strength.
| Brinell Indentation Diameter mm |
Brinell Hardness Number |
Rockwell Hardness Number |
Rockwell Superficial Hardness Number Superficial
Diamond Penetrator |
Tensile Strength (approx.) 1000 psi
|
| Standard Ball |
Tungsten- Carbide Ball |
B Scale |
C Scale |
15N Scale |
30N Scale |
45N Scale |
| 2.45 |
|
627 |
58.70 |
89.60 |
76.30 |
65.10 |
|
347 |
| 2.50 |
|
601 |
|
57.30 |
89.00 |
75.10 |
63.50 |
328 |
| 2.55 |
|
578 |
|
56.00 |
88.40 |
73.90 |
62.10 |
313 |
| 2.60 |
|
555 |
|
54.70 |
87.80 |
72.70 |
60.60 |
298 |
| 2.65 |
|
534 |
|
53.50 |
87.20 |
71.60 |
59.20 |
288 |
| 2.70 |
|
514 |
|
52.10 |
86.50 |
70.30 |
57.60 |
274 |
| 2.75 |
|
495 |
|
51.00 |
85.90 |
69.40 |
56.10 |
264 |
| 2.80 |
|
477 |
|
49.60 |
85.30 |
68.20 |
54.50 |
252 |
| 2.85 |
|
461 |
|
48.50 |
84.70 |
67.20 |
53.20 |
242 |
| 2.90 |
|
444 |
|
47.10 |
84.00 |
65.80 |
51.50 |
230 |
| 2.95 |
429 |
429 |
|
45.70 |
83.40 |
64.60 |
49.90 |
219 |
| 3.00 |
415 |
415 |
|
44.50 |
82.80 |
63.50 |
48.40 |
212 |
| 3.05 |
401 |
401 |
|
43.10 |
82.00 |
62.30 |
46.90 |
202 |
| 3.10 |
388 |
388 |
|
41.80 |
81.40 |
61.10 |
45.30 |
193 |
| 3.15 |
375 |
375 |
|
40.40 |
80.60 |
59.90 |
43.60 |
184 |
| 3.20 |
363 |
363 |
|
39.10 |
80.00 |
58.70 |
42.00 |
177 |
| 3.25 |
352 |
352 |
|
37.90 |
79.30 |
57.60 |
40.50 |
170 |
| 3.30 |
341 |
341 |
|
36.60 |
78.60 |
56.40 |
39.10 |
163 |
| 3.35 |
331 |
331 |
|
35.50 |
78.00 |
55.40 |
37.80 |
158 |
| 3.40 |
321 |
321 |
|
34.30 |
77.30 |
54.30 |
36.40 |
152 |
| 3.45 |
311 |
311 |
|
33.10 |
76.70 |
53.30 |
34.40 |
147 |
| 3.50 |
302 |
302 |
|
32.10 |
76.10 |
52.20 |
33.80 |
143 |
| 3.55 |
293 |
293 |
|
30.90 |
75.50 |
51.20 |
32.40 |
139 |
| 3.60 |
285 |
285 |
|
29.90 |
75.00 |
50.30 |
31.20 |
136 |
| 3.65 |
277 |
277 |
|
28.80 |
74.40 |
49.30 |
29.90 |
131 |
| 3.70 |
269 |
269 |
|
27.60 |
73.70 |
48.30 |
28.50 |
128 |
| 3.75 |
262 |
262 |
|
26.60 |
73.10 |
47.30 |
27.30 |
125 |
| 3.80 |
255 |
255 |
|
25.40 |
72.50 |
46.20 |
26.00 |
121 |
| 3.85 |
248 |
248 |
|
24.20 |
71.70 |
45.10 |
24.50 |
118 |
| 3.90 |
241 |
241 |
100.00 |
22.80 |
70.90 |
43.90 |
22.80 |
114 |
| 3.95 |
235 |
235 |
99.00 |
21.70 |
70.00 |
42.90 |
21.50 |
111 |
| 4.00 |
229 |
229 |
98.20 |
20.50 |
69.70 |
41.90 |
20.10 |
109 |
| 4.05 |
223 |
223 |
97.30 |
|
|
|
|
104 |
| 4.10 |
217 |
217 |
63.40 |
|
|
|
|
103 |
| 4.15 |
212 |
212 |
95.50 |
|
|
|
|
100 |
| 4.20 |
207 |
207 |
94.60 |
|
|
|
|
99 |
| 4.25 |
201 |
201 |
93.80 |
|
|
|
|
97 |
| 4.30 |
197 |
197 |
92.80 |
|
|
|
|
94 |
| 4.35 |
192 |
192 |
91.90 |
|
|
|
|
92 |
| 4.40 |
187 |
187 |
90.70 |
|
|
|
|
90 |
| 4.45 |
183 |
183 |
90.00 |
|
|
|
|
89 |
| 4.50 |
179 |
179 |
89.00 |
|
|
|
|
88 |
| 4.55 |
174 |
174 |
87.80 |
|
|
|
|
86 |
| 4.60 |
170 |
170 |
86.80 |
|
|
|
|
84 |
| 4.65 |
167 |
167 |
86.00 |
|
|
|
|
83 |
| 4.70 |
163 |
163 |
85.00 |
|
|
|
|
82 |
| 4.80 |
156 |
156 |
82.90 |
|
|
|
|
80 |
| 4.90 |
149 |
149 |
80.80 |
|
|
|
|
73 |
| 5.00 |
143 |
143 |
78.70 |
|
|
|
|
71 |
| 5.10 |
137 |
137 |
76.40 |
|
|
|
|
67 |
| 5.20 |
131 |
131 |
74.00 |
|
|
|
|
65 |
| 5.30 |
126 |
126 |
72.00 |
|
|
|
|
63 |
| 5.40 |
121 |
121 |
69.00 |
|
|
|
|
60 |
| 5.50 |
116 |
116 |
67.60 |
|
|
|
|
58 |
| 5.60 |
111 |
111 |
65.70 |
|
|
|
|
56 |
Torque Tensioning
Screw Point Types
Pilot Hole Sizes
Bolt & Screw Head Types
Weights per Thousand
Unified External Screw Threads
Rod & Bolt Diameters
Metric Conversions
Hole Sizes for Die Casting
Material Strength
Drive Tool Sizes
Hardness Conversions
|