Fraxinus Genus
ORIGIN:
The Fraxinus genus (ash) family contains nearly 70 species. For this feature, we will focus only on white ash (Fraxinus Americana) and black ash (Fraxinus Nigra), two of the more-common ash species used in the flooring industry. White and black ash are found primarily in the eastern United States and into eastern Canada.
USES:
Commonly used in flooring, furniture, millwork, tool handles, baseball bats, boat oars, boatbuilding, guitar bodies, decorative veneers, and basket weaving.
COLOR:
The heartwood of ash tends to be light to medium brown. The sapwood can be very wide and tends to be beige or light brown and not always clearly demarcated from the heartwood. White ash tends to have a lighter heartwood color than black ash.
GRAIN:
The grain is bold, straight, regular, and uneven with moderately open, occasional wavy figuring. White ash tends to have slightly wider spacing between growth rings than black ash.
VARIATIONS WITHIN SPECIES AND GRADES:
Sometimes confused with hickory; the zone of the large pores is more distinctive in ash, similar to that of red oak.
HARDNESS (JANKA):
- White ash averages 1320
- Black ash averages 850
DIMENSIONAL STABILITY: ABOVE AVERAGE
- White ash has a dimensional stability factor of 4.9 percent (radial) and 7.8 percent (tangential), meaning this species may shrink/swell up to 7.8 percent of its given width, depending on how it’s cut, when going from green (30 percent MC) to oven-dried.
- Black ash has a dimensional stability factor of 5.0 percent (radial) and 7.8 percent (tangential), meaning this species may shrink/swell up to 7.8 percent of its given width, depending on how it’s cut when going from green (30 percent MC) to oven-dried.
DIMENSIONAL CHANGE COEFFICIENT:
- White ash = .00169 (radial), .00274 (tangential)
- Black ash = .00172 (radial), .00274 (tangential)
SPECIFIC GRAVITY:
- White ash = .55
- Black ash = .45
NAILING:
No known issues with nailing ash.
SANDING:
Sands satisfactorily and similarly to red oak when following NWFA Sand and Finish Guidelines. Accepts stain well, but it is often required to bring the sanding sequence to a higher grit to minimize visible scratches. Springwood will be pronounced when color is added.
THREATS:
A non-native beetle known as the emerald ash borer (Agrilus Planipennis) bores into the tree and feeds on the inner bark, which eventually kills the tree. These beetles are responsible for the death of tens of millions of ash trees across the United States and Canada since its discovery in 2002.
Sources: The Wood Database; Copyright © 2008-2016, Eric Meier | Wood Handbook (Wood as an Engineering Material), USDA Forest Products Laboratory | A Guide to the Useful Woods of the World; Copyright © 2001, James H. Flynn, Jr. and Charles D. Holder | Missouri Dept. of Conservation.