Wood species
Mockernut hickory wood
Mockernut hickory is a hardwood (Carya tomentosa). At 12% moisture content it has a Janka hardness of 1,970 lbf (8,763 N) and it weighs about 50 lb/ft³ (806 kg/m³), 4.2 lb (1.9 kg) per board foot.
Also called: Carya tomentosa.
Key numbers
- Janka hardness, 12% MC
- 1,970 lbf (8,763 N)
- Green: 1,440 lbf (6,405 N)
- Weight at 12% MC
- 50 lb/ft³ (806 kg/m³)
- 4.2 lb per board foot
- Specific gravity (oven-dry weight)
- 0.72 at 12% MC volume
- 0.64 on green volume
- Shrinkage, green to oven-dry
- 11.0% tangential
- Radial 7.7%, volumetric 17.8%
One source: USDA Forest Products Laboratory, the authority for species properties it measured
Why: Measured by the USDA Forest Products Laboratory; mockernut hickory's density is worked from its specific gravity with the Handbook's own equation.
How much mockernut hickory moves
A 12 in wide flatsawn board of mockernut hickory that goes from 6% to 12% moisture content swells about 0.3 in (about 9/32 in, 7.5 mm). Quartersawn, the same board moves about 0.19 in (about 3/16 in, 4.7 mm). Flatsawn faces move 1.4 times as much as quartersawn ones, because the wood shrinks 11.0% around the growth rings but only 7.7% across them.
Worked with the Wood Handbook's dimensional change coefficients for mockernut hickory (the Handbook gives one row, "Hickory, true", for the group) (Table 13-5: 0.00411 tangential, 0.00259 radial per 1% change in moisture content), which hold between 6% and 14%. Individual boards vary: the Handbook gives shrinkage a coefficient of variation of about 15% (p. 4-11).
Color, grain and working
- Color
- White, usually wide sapwood and reddish heartwood, as for all the true hickories.
- Working and character
- The Handbook describes the true hickories together: exceptionally tough, heavy, hard and strong, and they shrink considerably in drying.
- Uses
- High-quality true hickory goes into tool handles, ladder rungs, athletic goods and dowels; hickory wood and chips also flavor smoked meat.
Table 13-5 gives one movement row for the true hickories as a group, so the movement figures are the group’s.
Adapted in our own words from the Wood Handbook, Chapter 2, p. 2-7.
Strength
Bending strength is the modulus of rupture (MOR); stiffness is the modulus of elasticity (MOE). Clear, straight-grained samples of mockernut hickory tested by the Forest Products Laboratory (Wood Handbook Table 5-3b). Knots and cross grain make lumber weaker than these clear samples (Handbook Chapter 5).
| Property | Green | 12% MC |
|---|---|---|
| Bending strength (MOR) | 11,100 psi (77 MPa) | 19,200 psi (132 MPa) |
| Stiffness (MOE) | 1,570,000 psi (10.8 GPa) | 2,220,000 psi (15.3 GPa) |
| Crushing strength (compression parallel to grain) | 4,480 psi (31 MPa) | 8,940 psi (62 MPa) |
| Compression perpendicular to grain | 810 psi (6 MPa) | 1,730 psi (12 MPa) |
| Shear parallel to grain | 1,280 psi (9 MPa) | 1,740 psi (12 MPa) |
| Tension perpendicular to grain | — | — |
A dash means the Handbook prints no value; none is filled in.
Dust and health
- Wood dust is classed as carcinogenic to humans (Group 1) by the International Agency for Research on Cancer, chiefly for cancers of the nose and sinuses.
- NIOSH recommends keeping wood dust exposure to 1 mg/m³ of total dust, as quoted in OSHA's sawmill guidance.
This is what the named authorities publish, not medical advice.
Compare with
Buying and finishing mockernut hickory
Work it out for your project
- Rank woods for your project with the species picker
Weigh mockernut hickory against other woods on hardness, weight, movement and color, every figure from the Wood Handbook.
Why these numbers
Why these numbers?
The situation
The USDA Forest Products Laboratory measured mockernut hickory at 1,970 lbf of side hardness at 12% moisture content, on clear, straight-grained samples (Wood Handbook Table 5-3b).
One source: USDA Forest Products Laboratory, the authority for species properties it measured , sources [1]
What that means
Side hardness (Janka) is the load needed to press a 0.444 in (11.28 mm) steel ball halfway into the wood across the grain; a higher number dents less (Handbook p. 5-5).
One source: USDA Forest Products Laboratory, the authority for species properties it measured , sources [1]
So
Density at 12% is water's density × specific gravity × (1 + 0.12) (Handbook Eq. 4-14): 62.43 × 0.72 × 1.12.
Arithmetic: exact by definition , sources [1]
The number
About 50 lb/ft³, or 4.2 lb per board foot (1/12 ft³), at 12% moisture content.
Arithmetic: exact by definition
Sources