White Aluminum Oxide Lapping Compound — Product & Application Description
White aluminum oxide lapping compound is a precision abrasive paste used for fine grinding, lapping, polishing, and finishing of hard materials. It consists of high-purity white fused alumina (white aluminum oxide, Al₂O₃) abrasive grains uniformly dispersed in a lubricating carrier medium such as mineral oil, grease, or water-based binder.




| Typical Chemical composition | |
| AL2O3 | 99.3%min |
| SiO2 | 0.06% |
| Na2O | 0.3%max |
| Fe2O3 | 0.05%max |
| CaO | 0.04%max |
| MgO | 0.01%max |
| K2O | 0.02#max |
| Typical physical properties | |
| Hardness: | Mohs:9.0 |
| Maximum service temperature: | 1900 ℃ |
| Melting Point: | 2250 ℃ |
| Specific Gravity: | 3.95g/cm3 |
| Volume density | 3.6g/cm3 |
| Bulk density(LPD): | 1.75-1.95 g/cm3 |
| Color: | White |
| Particle shape: | Angular |
| Available size: | |
| FEPA | F230 F240 F280 F320 F360 F400 F500 F600 F800 F1000 F1200 F1500 |
| JIS | 240# 280# 320# 360# 400# 500# 600# 700# 800# 1000# 1200# 1500# 2000# 2500# 3000# 4000# 6000# 8000# 10000# |
| ITEM | D0(um) | D3(um) | D50(um) | D94(um) |
| #240 | <127 | <103 | 57.0±3.0 | >40 |
| #280 | <112 | <87 | 48.0±3.0 | >33 |
| #320 | <98 | <74 | 40.0±2.5 | >27 |
| #360 | <86 | <66 | 35.0±2.0 | >23 |
| #400 | <75 | <58 | 30.0±2.0 | >20 |
| #500 | <63 | <50 | 25.0±2.0 | >16 |
| #600 | <53 | <41 | 20.0±1.5 | >13 |
| #700 | <45 | <37 | 17.0±1.5 | >11 |
| #800 | <38 | <31 | 14.0±1.0 | >9.0 |
| #1000 | <32 | <27 | 11.5.±1.0 | >7.0 |
| #1200 | <27 | <23 | 9.5±0.8 | >5.5 |
| #1500 | <23 | <20 | 8.0±0.6 | >4.5 |
| #2000 | <19 | <17 | 6.7±0.6 | >4.0 |
| #2500 | <16 | <14 | 5.5±0.5 | >3.0 |
| #3000 | <13 | <11 | 4.0±0.5 | >2.0 |
| #4000 | <11 | <8.0 | 3.0±0.4 | >1.8 |
| #6000 | <8.0 | <5.0 | 2.0±0.4 | >0.8 |
| #8000 | <6.0 | 3.5 | 1.2±0.3 | >0.6 |
Key Characteristics
- Extreme hardness & high wear resistance
White aluminum oxide has a Mohs hardness of approximately 9, providing strong cutting ability and consistent material removal during lapping.
- High purity & low contamination
Produced from high-grade alumina, it contains minimal impurities and avoids iron contamination, making it ideal for finishing stainless steel, carbide, ceramics, and precision components.
- Stable particle size distribution
Uniform grain size ensures smooth, scratch-free surfaces and controllable surface roughness.
- Good dispersion & lubricity
The carrier fluid prevents grain agglomeration, reduces heat generation, and improves surface finish quality.
- Chemical inertness
Resists acids, alkalis, and oxidation, suitable for lapping precision parts in corrosive environments.
Typical Applications
- Lapping and finishing of carbide cutting tools, dies, and molds
- Precision finishing of bearings, valves, gears, and hydraulic components
- Polishing of ceramic components, sapphire, and optical parts
- Fine honing of cylinder liners, pump parts, and aerospace components
- Surface treatment of stainless steel and high-speed steel parts
Available Grades
Available in various particle sizes (grits), from coarse for stock removal to ultra-fine for mirror polishing, to meet different precision lapping and finishing requirements.