CutMath

Purpleheart

Peltogyne spp. · hardwood · Central/South America · moderate movement

Field data
  • Janka hardness 2,520 lbfred oak ≈ 1,290 lbf
  • Density ≈ 60 lb/ft³specific gravity 0.86 at 12% MC
  • Shrinkage — tangential 6.1%flatsawn width, green → ovendry
  • Shrinkage — radial 3.2%quartersawn width
  • T/R ratio 1.9 : 1higher = more cupping in flatsawn stock

Shop notes Cuts brown, oxidizes violet, and behaves better than its density suggests — moderate movement, brutal on edges. Heat from dull tools turns it muddy.

Seasonal movement at a glance

Width change for purpleheart across a typical indoor year — 6% moisture content in the heated winter to 12% in a humid summer:

Board widthFlatsawnQuartersawn
6″ 3/32″ (0.078″) 1/32″ (0.041″)
12″ 5/32″ (0.157″) 3/32″ (0.082″)
24″ 5/16″ (0.314″) 5/32″ (0.165″)
36″ 15/32″ (0.471″) 1/4″ (0.247″)

Run your own numbers

Different width, different climate swing — the calculator below is preset to purpleheart:

Board & conditions
Grain
Conditions given as

Typical swings:

Movement estimate
    Estimate Figures use species-average shrinkage from the USDA Wood Handbook and the standard shop movement formula. Individual boards vary — leave margin, especially with flatsawn stock.

    Purpleheart questions

    How much does purpleheart move with the seasons?

    A 12″-wide flatsawn purpleheart board moves about 5/32″ across a typical indoor swing from 6% to 12% moisture content; quartersawn, about 3/32″. Its tangential shrinkage is 6.1% and radial 3.2% (green to ovendry) — a moderate-movement wood.

    How hard is purpleheart?

    Purpleheart rates about 2,520 lbf on the Janka scale — noticeably harder than red oak (red oak is roughly 1,290 lbf). Density runs about 60 lb/ft³ at indoor moisture levels.

    Is purpleheart good for wide panels and tabletops?

    Yes, with normal precautions: its 1.9:1 tangential-to-radial ratio is moderate. Still fasten solid tops so they can move across their width.

    Similar species

    Jatoba (Brazilian Cherry) · Persimmon · Pignut Hickory · African Padauk · Wenge · Shagbark Hickory

    Shrinkage, specific gravity, and hardness from the Wood Handbook, FPL-GTR-282 (2021 edition), USDA Forest Products Laboratory (public domain). Values are species averages — individual boards vary with growth conditions and how they were dried.