Comparing Shagbark Hickory and Pecan for Epoxy Builds
Shagbark hickory and pecan both belong to the hickory group, yet they exhibit distinct mechanical and physical behaviors. When fabricating an epoxy river table or wide tabletop, understanding how each species responds to load, surface impact, and moisture fluctuation is essential. The figures below draw from the USDA Forest Products Laboratory reference, Wood Handbook (FPL-GTR-282).
Weight and Density
At 12% moisture content, Shagbark hickory has a specific gravity of 0.72, while pecan sits at 0.66. In green condition, Shagbark hickory measures 0.64 compared to 0.60 for pecan. Shagbark hickory produces a heavier slab, which increases the total dead weight of the finished furniture piece. While this extra mass lends a substantial, grounded feel to a dining table or conference top, it also places greater demands on table bases, fasteners, and handling during the pour and surfacing stages.
Dent Resistance and Surface Hardness
Surface toughness is critical for dining and working surfaces that see frequent contact. At 12% moisture content:
- Side hardness: Shagbark hickory tests at 1,880 lbf, whereas pecan measures 1,820 lbf.
- Compression perpendicular to grain: Shagbark hickory reaches 1,760 lbf/in², compared to 1,720 lbf/in² for pecan.
Both species offer exceptional dent resistance and will resist dinging, dropped objects, and localized crushing under heavy objects. In green wood, Shagbark hickory retains higher values (840 lbf/in² compression perpendicular to grain and 1,460 lbf hardness) than green pecan (780 lbf/in² and 1,310 lbf), but once dried to service levels, their surface resilience is very similar.
Stiffness and Strength for Spans and Overhangs
Where these two woods diverge significantly is in structural rigidity and bending capacity. At 12% moisture content, Shagbark hickory records a modulus of rupture of 20,200 lbf/in² and a modulus of elasticity of 2.16 million lbf/in². In contrast, pecan provides a modulus of rupture of 13,700 lbf/in² and a modulus of elasticity of 1.73 million lbf/in².
Shagbark hickory offers substantially greater stiffness and bending strength. For long tables with extended spans between trestles, or for deep unsupported overhangs at table ends, Shagbark hickory deflects less under load. Pecan remains a strong hardwood, but it allows more flex across broad, unsupported spans.
Seasonal Movement and Shrinkage
Whenever wood is locked against a rigid epoxy resin channel, dimensional stability is vital. Wood expands and contracts across seasonal humidity changes, generating stress along the epoxy bond line.
Total shrinkage from green to ovendry highlights the overall shrinkage volume:
- Radial shrinkage: 7.0% for Shagbark hickory versus 4.9% for pecan.
- Tangential shrinkage: 10.5% for Shagbark hickory versus 8.9% for pecan.
- Volumetric shrinkage: 16.7% for Shagbark hickory versus 13.6% for pecan.
Looking at in-service seasonal changes, the dimensional change coefficients show that pecan moves less per unit change in moisture content. Pecan has a radial coefficient of 0.00169 and a tangential coefficient of 0.00315, compared to Shagbark hickory at 0.00259 radial and 0.00411 tangential. However, Shagbark hickory features a tangential-to-radial (T/R) shrinkage ratio of 1.5, whereas pecan calculates to 1.8. While pecan moves less overall, Shagbark hickory exhibits slightly more uniform dimensional change between its radial and tangential faces.
Figures from the USDA Wood Handbook (FPL-GTR-282), Tables 4-1, 4-3, 5-3b, 13-5 and 14-1. Clear, straight-grained specimens; real slabs vary.
| Property | Shagbark hickory | Pecan |
|---|---|---|
| Specific gravity (12% MC) | 0.72 | 0.66 |
| Side hardness, lbf (12% MC) | 1,880 | 1,820 |
| Modulus of rupture, lbf/in² (12% MC) | 20,200 | 13,700 |
| Modulus of elasticity, million lbf/in² (12% MC) | 2.16 | 1.73 |
| Compression perpendicular to grain, lbf/in² (12% MC) | 1,760 | 1,720 |
| Radial shrinkage, green to ovendry (%) | 7.0 | 4.9 |
| Tangential shrinkage, green to ovendry (%) | 10.5 | 8.9 |
| Volumetric shrinkage, green to ovendry (%) | 16.7 | 13.6 |
| Dimensional change coefficient, tangential (per 1% MC) | 0.00411 | 0.00315 |
| Dimensional change coefficient, radial (per 1% MC) | 0.00259 | 0.00169 |
| Tangential/radial shrinkage ratio (calculated) | 1.5 | 1.8 |
| Heartwood decay resistance (Table 14-1) | Slightly or nonresistant | Slightly or nonresistant |
Heartwood Decay Resistance
According to Table 14-1 of the Wood Handbook, the heartwood of both Shagbark hickory and pecan is classified as slightly or nonresistant to decay. Because neither species has natural rot resistance, both are best suited for climate-controlled indoor environments. Follow the resin manufacturer’s technical data sheet for proper sealing and encapsulation along the river edges to preserve wood integrity.
Which to Pick When
- Choose Shagbark hickory if your tabletop involves long unsupported spans, thin cross-sections, or aggressive end overhangs where maximum bending strength (20,200 lbf/in² MOR) and stiffness (2.16 million lbf/in² MOE) are necessary to stop sagging.
- Choose Pecan if minimizing seasonal width fluctuation across the epoxy seam is your priority. With lower shrinkage across the board (8.9% tangential and 4.9% radial) and lower dimensional change coefficients, pecan exerts lower movement forces against the cured epoxy channel during indoor humidity swings.
Sources
Published October 28, 2026. Sources are linked in the text.
Header image: original graphic by BigEpoxy.com.
Staff note: For joint design and live-edge bonding, shear strength parallel to the grain at 12% moisture content is 2,430 psi for Shagbark hickory versus 2,080 psi for Pecan, providing Shagbark with higher internal resistance against parallel shear loads along the glue line. (Source: USDA Forest Products Laboratory, Wood Handbook (FPL-GTR-282, 2021).)