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Blunting Effect Boring Common Names Common Uses Countries of Distribution Cutting Resistance Distribution Overview Drying Defects Ease of Drying Environmental Profile Family Name Gluing Grain Heartwood Color Kiln Schedules Mortising Movement in Service Nailing Natural Durability Numerical Data Odor Planing Product Sources References Regions of Distribution Resistance to Abrasion Resistance to Impregnation Response to Hand Tools Sanding Sapwood Color Scientific Name Screwing Staining Steam Bending Strength Properties Texture Trade Name Tree Size Turning Veneering Qualities		Scientific Name Quercus macrocarpa Trade Name Bur oak Family Name Fagaceae Common Names Blue oak, Bur Oak, Cucharillo, Encino, Encino negro, Mamecillo, Mossy overcup oak, Mossycup oak, Oak, Roble, Roble amarillo, Roble colorado, Roble encino, Roblecito, Scrub oak, White oak Regions of Distribution North America Countries of Distribution  [VIEW MAP] Canada, United States Common Uses Cooperages, Core Stock, Crossties, Decorative veneer, Domestic flooring, Factory flooring, Figured veneer, Flooring, Foundation posts, Fuelwood, Mine timbers, Parquet flooring, Pile-driver cushions, Piling, Plain veneer, Poles, Posts, Railroad ties, Stakes, Sub-flooring, Utility poles, Veneer Environmental Profile Abundant/Secure Widespread Secure in many areas of its range Rank of relative endangerment based on number of occurences globally. May be rare in some parts of its range, especially at the periphery Globally secure Generally secure within its natural habitat Data source is World Conservation Monitoring Center Data source is Nature Conservancy Abundant Officially classified as Extinct in the state of Delaware and is suspected to be either Extinct, Endangered, Vulnerable, or Rare in Maine Distribution Overview Bur oak occurs in Manitoba, New Brunswick, Ontario, Quebec, and Saskatchewan, all in Canada. In the United States it is found in the states of Alabama, Arkansas, Indiana, Kansas, Kentucky, Maine, Michigan, Minnesota, Missouri, North Carolina, North Dakota, Nebraska, New Hampshire, New Jersey, Louisiana, Delaware, New Mexico, New York, Ohio, Oklahoma, Pennsylvania, Rhode Island, South Dakota, Tennessee, Maryland, Massachusetts, Connecticut, Iowa, Illinois, Mississippi, Montana, Texas, Virginia, Vermont, Wisconsin, West Virginia, and Wyoming. The tree is often found in pure stands on dry uplands, limestone and gravelly ridges, sandy plains, and loamy slopes to moist flood plains of streams. Heartwood Color Brown Red Purple Pink Pinkish tinge Variations in color and grain are considerable, but are not as pronounced as in red oak Varies in color from light tan or pale yellow brown to pale or dark brown. Sapwood Color Brown White Pink Red Grey Width varies Whitish to light brown Grain Figure Open Rays are typically longer than those in red oak. Crotches, swirls and burls, are occasionally present and plainswan boards have a plumed or flare-grained appearance. The grain pattern is tighter, and figuring is usually lower in riftsawn lumber. Quartersawn materials often have a flake pattern which is sometimes referred to as tiger rays or butterflies Texture Medium Natural Durability Heartwood highly resistant to decay Logs are susceptible to severe attack by ambrosia beetles, and standing trees and logs are also readily attacked by forest longhorn or Butrespid beetles Odor Has an odor No specific smell or taste Kiln Schedules US=Upland T4-C2/T3-C1 US=Lowland T2-C1 Drying Defects Internal Honeycombing Possible Ring Shakes Collapse Discoloration Surface checks Ring failure Honeycombing possible Gray sapwood stain End checks Defects include:uneven moisture, chemical stains, iron stains, and are attributable to wetwood (usually in old growth) Collapse Ease of Drying Moderately Difficult to Difficult Difficult Tree Size Tree height is 10-20 m Tree height is 20-30 m The tree is planted for shade, ornament, and shelterbelts Product Sources For commercial purposes, several species in the white oak group, including Bur oak, are mixed together. Supplies of white oak are abundant, especially in the form of veneers, at moderate prices. Blunting Effect Moderate Moderate dulling effect on cutting edges Boring Very good to excellent results Fairly easy to very easy Responds readily to preservative treatment by either open tank or pressure methods Bored surfaces usually clean Cutting Resistance Cutting resistance is generally medium but is variable. Cross-cutting and narrow-bandsawing are satisfactory Gluing Fair to Good Results Fairly Easy to Very Easy Satisfactory gluing properties Mortising Fair to Good Results Fairly Easy to Very Easy Very good mortising qualities Movement in Service Fair to Good Stability - Medium Movement Moderate dimensional stability after seasoning Medium Nailing Pre-Boring Recommended Pre-boring recommended Difficult to nail Planing Fair to Good Results Fairly Easy to Very Easy Good planing properties A cutting angle of 20 degrees is recommended Machining characteristics of white oak timbers are reported to vary with species and rate of growth. Softer timber from slow-growth trees are generally easier to work Resistance to Abrasion Highly resistant to wear Good for flooring Resistance to Impregnation Resistant sapwood Resistant heartwood Permeable sapwood Permeable heartwood Sapwood is moderately resistant Heartwood responds poorly to preservative treatment High natural resistance to decay allows the heartwood to be used outdoors without chemical protection. Response to Hand Tools Responds Readily Easy to Work Timber from slow-growth white oak trees are softer and are easier to work with hand tools Sanding Fairly Easy to Very Easy Fair to Good Results Very Good to Excellent Results Yields smooth surfaces Easy to sand Screwing Fair to Good Results Fairly Easy to Very Easy Good screwing properties Turning Very Good to Excellent Results Fairly Easy to Very Easy Fair to Good Results Yields clean surfaces Easy to turn Veneering Qualities Some logs are converted into veneers. Quartered veneer are flake figured, while the very popular straight line figure is prominent in rift cut veneer Steam Bending Very Good to Excellent Results Exceptional resistance to harmful effects of weather Defect free material bends to very small radius of curvature Proper precautions should be taken to prevent chemical staining of steamed wood in contact with iron or steel Staining Very Good to Excellent Results Some finishing products, especially those with high water content such as bleach and water-based finishes, may react with tannins to turn the wood green or brown. Strength Properties Low stiffness Crushing strength = medium Bending strength (MOR) = medium Their working properties are reported to depend to a large extent on the rate of growth of the trees: slow grown trees are reported to respond better to hand and machine tools. Faster grown southern species are reported to yield wood that is harder than the slower growing Appalachian trees. Numerical Data Item Green Dry English Bending Strength 6566 11531 psi Crushing Strength 701 1220 psi Hardness 1342 lbs Impact Strength 60 28 inches Maximum Crushing Strength 2920 5723 psi Shearing Strength 1784 psi Static Bending 2646 5978 psi Stiffness 818 1049 1000 psi Work to Maximum Load 14 15 inch-lbs/in3 Specific Gravity 0.58 0.64 Weight 59 44 lbs/ft3 Radial Shrinkage 4 % Tangential Shrinkage 7 % Volumetric Shrinkage 13 % Item Green Dry Metric Bending Strength 461 810 kg/cm2 Crushing Strength 49 85 kg/cm2 Hardness 608 kg Impact Strength 152 71 cm Maximum Crushing Strength 205 402 kg/cm2 Shearing Strength 125 kg/cm2 Static Bending 186 420 kg/cm2 Stiffness 57 73 1000 kg/cm2 Work to Maximum Load 0.98 1.05 cm-kg/cm3 Specific Gravity 0.58 0.64 Weight 945 705 kg/m3 Radial Shrinkage 4 % Tangential Shrinkage 7 % References Boone, R.S., C.J. Kozlik, P.J. Bois and E.M. Wengert. 1988. Dry Kiln Schedules for Commercial Woods: Temperate and Tropical. United States Department of Agriculture, Forest Service, Forest Products Laboratory, General Technical Report FPL-GTR-57, Madison, Wisconsin. Little, E.L. 1980. The Audubon Society Field Guide to North American Trees - Eastern Region. Published by Arthur A. Knopf, New York. Panshin, A.J. and C. deZeeuw. 1980. Textbook of Wood Technology, 4th Edition. McGraw-Hill Series in Forest Resources. McGraw-Hill Book Company, New York. USDA. 1987. Wood Handbook - Wood as an Engineering Material, Forest Service, Agriculture Handbook No. 72, Forest Products Laboratory, Madison, Wisconsin. USDA. 1988. Dry Kiln Operators Manual, Preliminary Copy. Forest Service, Forest Products Laboratory, Madison, Wisconsin.