Ash vs oak
White ash and the oaks are close in hardness and both show open grain. Ash is the lighter of the three and, across a flatsawn board, it moves less than either oak.
- White oak is about 3% harder than white ash.
- White oak is about 13% heavier than white ash.
- White oak has about 37% more movement across a flatsawn board than white ash.
- White ash is about 2% harder than northern red oak.
- Northern red oak is about 5% heavier than white ash.
- Northern red oak has about 11% more movement across a flatsawn board than white ash.
Each column is the species its page leads with: white ash for ash, northern red oak for red oak.
Side by side
| Property | Ash | White oak | Red oak |
|---|---|---|---|
| Janka hardness, 12% MC | 1,320 lbf | 1,360 lbf | 1,290 lbf |
| Weight, 12% MC | 42 lb/ft³ (672 kg/m³) | 47.5 lb/ft³ (762 kg/m³) | 44.1 lb/ft³ (706 kg/m³) |
| Specific gravity, 12% MC | 0.60 | 0.68 | 0.63 |
| Tangential shrinkage | 7.8% | 10.5% | 8.6% |
| Radial shrinkage | 4.9% | 5.6% | 4.0% |
| 12 in flatsawn board, 6% → 12% MC | 0.197 in | 0.271 in | 0.219 in |
| 12 in quartersawn board, 6% → 12% MC | 0.122 in | 0.14 in | 0.099 in |
| Bending strength (MOR), 12% MC | 15,400 psi | 15,200 psi | 14,300 psi |
| Stiffness (MOE), 12% MC | 1.74 million psi | 1.78 million psi | 1.82 million psi |
| Crushing strength, 12% MC | 7,410 psi | 7,440 psi | 6,760 psi |
One source: USDA Forest Products Laboratory, the authority for species properties it measured
Wood Handbook Tables 5-3b, 4-3 and 13-5; weight and movement worked with its Eqs. 4-14 and 13-3. A dash means the Handbook prints no value.
What sets them apart
- Movement
- Table 13-5 puts white ash’s tangential coefficient at 0.00274 per 1% moisture change, against 0.00376 for white oak and 0.00304 for northern red oak, so a flatsawn ash board moves the least of the three. (Wood Handbook, p. 13-17)
- Strength
- Second-growth white ash is heavy, strong, hard and stiff with high shock resistance. White oak is somewhat heavier than red oak and has decay-resistant heartwood; red oak is heavy with fairly high shrinkage. (Wood Handbook, p. 2-4 and 2-9)
- Uses
- White ash goes into tool handles, oars, baseball bats, cabinets, furniture and flooring. White oak goes into tight barrels, boats, furniture and flooring; red oak into flooring, furniture and millwork. (Wood Handbook, p. 2-4 and 2-9)
- Availability
- The Handbook reports that the IUCN lists white, green, blue and black ash as critically endangered because of the emerald ash borer, and that infested trees are being harvested widely. (Wood Handbook, p. 2-4)
For any other pair, open each species page from the wood hub; every page uses the same layout and the same sources.