Table 1.

Callus growth over washers and area of wood discoloration one year after lag and washer installation using 2 methods of countersinking and not countersinking.

Tree speciesType of counter-skinkingCallus growth (mm)Wood discoloration (cm2)
Red oakdrill8.5 a*28.3 a
chisel4.1 b38.6 a
none0.2 c14.4 b
Beechdrill10.2 a17.6 a
chisel8.8 a19.4 a
none0.0 b8.7 b
  • * Means in the same column and species with the same letter are not significantly different (P= 0.05) according to the Student Newman Kuels test.