Skip to page content
USDA Forest Service

Research & Development Treesearch

Treesearch Home
About Treesearch
Contact Us
Research & Development
Forest Products Lab
International Institute of Tropical Forestry
Pacific Northwest
Pacific Southwest
Rocky Mountain
Southern Research Station
Help - We Participate  Government Made Easy

Global Forest Information Service

US Forest Service
P.O. Box 96090
Washington, D.C.

(202) 205-8333

You are here: Home / Search / Publication Information
Bookmark and Share

Publication Information

View PDF (1.1 MB bytes)

Title: Moisture content of southern pine as related to thrust, torque, and chip formation in boring

Author: McMillin, C. W.; Woodson, G. E.;

Date: 1972

Source: Forest Products Journal 22(11):55-59

Publication Series: Miscellaneous Publication

Description: Holes 3-1/2 inches deep were bored with a 1-inch spur machine bit in southern pine having specific gravity of 0.53 (ovendry weight and volume at 10.4 percent moisture). The bit was rotated at 2,400 rpm and removed chips 0.020 inch thick. For wood moisture contents ranging from ovendry to saturation, thrust was lower when boring along the grain (average 98 pounds) than across the grain (average 138 pounds), while torque was higher when boring along the grain (average 42 inch-pounds) than across the grain (average 33 inch-pounds). For both boring directions, torque and thrust increased with increasing moisture content to a maximum at about 5 to 10 percent, then decreased to a constant value at about the fiber-saturation point. For the type of bit tested, net power at the spindle required to cut 0.020-inch-thick chips at speeds of 2,400 rpm or less should not exceed 2 hp., regardless of boring direction or moisture content; thrust should not exceed 200 pounds. Chip types resembled those obtained in orthogonal cutting.

Publication Notes:

  • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
  • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
  • You may send email to to request a hard copy of this publication. (Please specify exactly which publication you are requesting and your mailing address.)



McMillin, C. W.; Woodson, G. E. 1972. Moisture content of southern pine as related to thrust, torque, and chip formation in boring. Forest Products Journal 22(11):55-59


 [ Get Acrobat ]  Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility

USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.