KNOWLEDGE
N.T. Ruddock leverages decades of experience to keep you informed
WHEEL BLAST
STEEL SHOT
The Effect Of Abrasive Size On Impact And Coverage
| Shot Size Pellets Per Round Relative Impact Value |
| 780 8,000 800 |
| 660 14,000 500 |
| 550 26,000 300 |
| 460 45,000 165 |
| 390 65,000 100 |
| 330 110,000 60 |
| 280 210,000 36 |
| 230 360,000 22 |
| 170 520,000 12 |
| 110 1,700,000 5 |
| 70 6,000,000 1 |
Relative Impact Values
From S-780 to S-280:
Adjacent Sizes (660 vs 550, 390 vs 330, etc.)
Larger Size – Two Thirds More Impact
Smaller Size – Half As Much Impact
Two Sizes Apart (660 vs 460, 390 vs 280, etc.)
Larger Size – Three Times More Impact
Smaller Size – One Third As Much Impact
From S-230 to S-70:
230 vs 170 – 230 Has 80% More Impact
230 vs 110 – 230 Has Four Times More Impact
170 vs 110 – 170 Has 2-1/2 Times More Impact
170 vs 70 – 170 Has 12 Times More Impact
110 vs 70 – 110 Has 5 Times More Impact
ABRASIVE CONSUMPTION FOR WHEEL BLAST
lbs / wheel hour
| S-170 | S-230 | S-280 | 2-330 | S-390 | S-460 | S-550 | S-660 | |
| 5 H.P. | 1.2 | 2.1 | 2.1 | 2.7 | 2.7 | 3.4 | 3.4 | 3.9 |
| 10 H.P. | 3.5 | 4.2 | 4.2 | 5.4 | 5.4 | 6.9 | 6.9 | 7.9 |
| 15 H.P. | 4.2 | 5.6 | 5.6 | 7.0 | 7.0 | 8.8 | 8.8 | 9.0 |
| 20 H.P. | 6.8 | 8.4 | 8.4 | 10.0 | 10.0 | 13.0 | 13.0 | 14.5 |
| 25 H.P. | 7.6 | 9.8 | 9.8 | 12.5 | 12.5 | 17.0 | 17.0 | 18.0 |
| 30 H.P. | 9.0 | 10.4 | 10.4 | 16.0 | 16.0 | 20.0 | 20.0 | 23.0 |
| 40 H.P. | 10.4 | 16.0 | 16.0 | 20.0 | 20.0 | 26.0 | 26.0 | 30.0 |
| 40 H.P. | 10.4 | 16.0 | 16.0 | 20.0 | 20.0 | 26.0 | 26.0 | 30.0 |
| 50 H.P. | 16.0 | 20.0 | 20.0 | 25.0 | 25.0 | 32.0 | 32.0 | 36.0 |
| 60 H.P. | 18.0 | 24.0 | 24.0 | 31.0 | 31.0 | 39.0 | 39.0 | 45.0 |
| 75 H.P. |
22.0 | 27.5 | 27.5 | 36.0 | 36.0 | 46.0 | 46.0 | 52.0 |
| 100 H.P. |
28.0 | 37.5 | 37.5 | 49.0 | 49.0 | 61.0 | 61.0 | 70.0 |
AIRBLAST INFORMATION
AIR REQUIRMENTS
| Nozzle | Size of Orifice | Volume of Air | Plus Helmet | Plus 50% (reserve) | Minimum Air Required |
| No. 4 | 1/4″ 6.5mm | 81 2.3 | 20 0.5 | 50 1.4 | 151 cfm 4.2 m3/min |
| No. 5 | 5/16″ 8.0mm | 137 3.9 | 20 0.5 | 79 2.2 | 236 cfm 6.6m3/min |
| No.6 | 3/8″ 9.5mm | 196 5.5 | 20 0.5 | 108 3.0 | 324 cfm 9.0 m3/min |
| No. 7 | 7/16″ 11.0mm | 254 7.2 | 20 0.5 | 137 3.9 | 411 cfm 11.6 m3/min |
| No. 8 | 1/2″ 12.5mm | 338 9.6 | 20 0.5 | 179 5.0 | 537 cfm 16.1 m3/min |
APPROXIMATE AIR CONSUMPTION (CFM) PER BLAST NOZZLE
AIR REQUIRMENTS
| 60 PSI | 70 PSI | 80 PSI | 90 PSI | 100 PSI | |
| NO. 2 – 1/8″ | 14 | 16 | 18 | 20 | 22 |
| NO. 3 – 3/16″ | 32 | 36 | 41 | 45 | 49 |
| NO. 4 – 1/4″ | 57 | 65 | 72 | 80 | 90 |
| NO. 5 – 5/16″ | 90 | 101 | 113 | 125 | 150 |
| NO. 6 – 3/8″ | 126 | 145 | 163 | 182 | 200 |
| NO. 7 – 7/16″ | 170 | 193 | 215 | 240 | 270 |
| NO. 8 – 1/2″ | 230 | 260 | 290 | 320 | 350 |
| NO. 10 – 5/8″ | 360 | 406 | 454 | 500 | 550 |
| NO. 12 – 3/4″ | 518 | 585 | 652 | 720 | 790 |
ABRASIVE/PROFILE COMPARATIVE CHART
The following chart should be used only for approximating the abrasive size required to obtain a specified anchor pattern. The standard metal used to obtain these results was hot rolled steel and tightly adhering mil scale. The resulting depth of anchor pattern will vary with the method used for measuring deaths as well as any one of the numerous other variables (type and hardness of steel, thickness of mil scale, degree of cleaning specified, etc.). This information can be used for centrifugal wheel as well as pressure blasting. Pressure blasting should be done using 90 – 100 PSI nozzle pressure. The death of anchor pattern used in this chart is an average and not a minimum or maximum depth obtainable. Consult local abrasive suppliers for specific technical data.
1 Mil Profile
G-80 Steel Grit
S-110 Steel Shot*
80 Mesh Garnet
100 Grit Aluminum Oxide
1.5 Mil Profile
G-50 Steel Grit
S-170 Steel Shot*
36 Mesh Garnet
50 Grit Aluminum Oxide
2 Mil Profile
G-40 Steel Grit
S-230 Steel Shot*
36 Mesh Garnet
36 Grit Aluminum Oxide
2.5 Mil Profile
G-40 Steel Grit
S-280 Steel Shot*
36 Mesh Garnet
24 Grit Aluminum Oxide
3-4 Mil Profile
G-25 Steel Grit
S-330 or 390 Steel Shot*
16 Mesh Garnet
16 Grit Aluminum Oxide
*Note: Steel shots alone will not give a good angular anchor pattern that should be used in combination with steel grit for best results.
N.T. Ruddock Company
26123 Broadway Ave.
Cleveland, OH 44146
Hours of operation:
8am – 5pm Monday -Friday
Or by appointment
