Black Locust (posts) and Pressure Treated Pine (fence)
Robinia pseudacacia (posts) / Pinus spp. (fence) • Hardwood (posts) and Softwood (fence)
Grain Pattern
Straight to interlocked in the posts; flat-sawn with prominent growth rings and knots in the fence rails.
Color Description
Posts show a dark, weathered grey-brown oxidation; fence rails are a yellowish-tan with greenish hues from Copper Azole or MCQ pressure treatment.
Hardness Rating
Posts: 1,700 lbf (Hard); Fence: 690 lbf (Soft)
Durability Rating
Posts: Very Durable (extremely rot resistant); Fence: Durable only via chemical treatment, susceptible to rot if untreated.
Common Uses
Outdoor structures, fence posts, decking, railroad ties, and landscaping.
Geographic Origin
Eastern North America (both species).
Market Value & Sustainability
Estimated Market Value
Posts: $4.00 - $6.00 per board foot; Fence: $1.50 - $2.50 per board foot.
Wood Age Estimate
Posts: 5-10 years (based on silvering and seasoning checks); Fence: 1-2 years (fresh appearance, minimal silvering).
Sustainability Status
Least Concern (IUCN); highly sustainable and often considered invasive in certain regions.
Workability
Posts are very hard and dull tools quickly; fence pine is easy to work but requires corrosion-resistant fasteners due to treatment chemicals.
Notable Features
Black Locust is renowned for its high density and natural rot resistance without chemicals; the fence wood contains chemical preservatives.
Finish Recommendations
Penetrating oil-based stain for both; allow treated pine to dry for 3-6 months before application.
Identification Confidence
High for the treated pine (characteristic color and knots); Medium for the posts based on outdoor context and weathered texture.