Technical guide
Abrasive selection guide
Choose the right abrasive for your application — shape, size and hardness explained, mapped to the Macloid Metalix product range.
Decision guide
Three decisions, one right abrasive
Work through shape, then size, then hardness — in that order. Each decision narrows the field until only one or two grades remain.
Choosing the right shape
Shot vs Grit
Round shot — when to choose it
- Peening action: induces compressive stress and improves fatigue life
- Produces low, rounded surface profile
- Longest media life and lowest dust output
- Ideal for cleaning, descaling and shot peening
- Best in airless wheel-blast systems
Angular grit — when to choose it
- Cutting action: fast scale and coating removal
- Sharp, deep anchor profile for high-build coatings
- Higher breakdown rate — shorter life than shot
- Etches harder, smoother substrates effectively
- Often blended with shot to balance profile and speed
Matching size to application
Size selection
Coarse media (S330–S930 / G10–G25)
- High kinetic energy per impact — strips heavy mill scale quickly
- Leaves a coarser profile, fewer impacts per kilogram
- Use for heavy descaling of castings, forgings and structural steel
- Requires more powerful blast equipment (high wheel speed / air pressure)
Fine media (S70–S230 / G40–G80)
- Many more impacts per pass — uniform, smooth finish
- Higher coverage for peening, lower removal rate for scale
- Ideal for cosmetic surfaces and precision coating anchor profiles
- Compatible with lower-power equipment and lighter substrates
Balancing cut speed and media life
Hardness guide
Standard hardness (40–51 HRC)
- Workhorse grade for general cleaning and peening
- Excellent durability — low breakdown, low dust
- Broad application across castings, forgings, structures
- Most economical choice for high-volume production
Hard grade (55–65 HRC)
- Cuts faster on tenacious scale and hard coatings
- Higher breakdown — increased fines and dust loads
- Use when cycle time on difficult scale justifies higher consumption
- Media must always be harder than the workpiece substrate
Quick reference
Application-to-product map
Find your application, read across for the recommended Macloid product, size and hardness.
| Application | Recommended product | Size range | Hardness |
|---|---|---|---|
| Heavy mill scale / rust removal | Steel Grit G25–G40 | G25–G40 | 55–65 HRC |
| General casting descaling | Steel Shot S230–S390 | S230–S390 | 40–51 HRC |
| Coating anchor profile | Steel Grit G40–G50 | G40–G50 | 55–65 HRC |
| Shot peening (fatigue life) | Cut Wire Shot (per Almen) | Per spec | 45–62 HRC |
| Cosmetic / fine finish | Steel Shot S70–S170 | S70–S170 | 40–51 HRC |
| Non-ferrous / stainless parts | Stainless Shot | Fine–medium | Substrate-matched |
Not sure which grade fits?
Talk to our engineers
Send us your substrate, machine type and target spec. Our engineers will recommend the exact grade, size and operating mix — and a sample to trial.