Plywood

===Aircraft===
[[File:De Havilland DH-98 Mosquito ExCC.jpg|thumb|[[de Havilland Mosquito|De Havilland DH-98 Mosquito]] was made of curved and glued veneers]]

High-strength plywood, also known as aircraft plywood, is made from mahogany, spruce and/or birch using adhesives with an increased resistance to heat and humidity. It was used in the construction of air assault gliders during [[World War II]] and also several [[fighter aircraft]], most notably the multi-role British [[De Havilland Mosquito|Mosquito]]. Nicknamed "The Wooden Wonder", plywood was used for the wing surfaces, and also flat sections such as bulkheads and the webs of the wing spars. The fuselage had exceptional rigidity from the bonded ply-balsa-ply 'sandwich' of its [[monocoque]] shell; elliptical in cross-section, it was formed in two separate mirror-image halves, using curved moulds.

Structural aircraft-grade plywood is most commonly manufactured from African mahogany, spruce or birch veneers that are bonded together in a hot press over hardwood cores of basswood or poplar or from European Birch veneers throughout. Basswood is another type of aviation-grade plywood that is lighter and more flexible than mahogany and birch plywood but has slightly less{{Citation needed|reason=da012|date=April 2013}} structural strength. Aviation-grade plywood is manufactured to a number of specifications including those outlined since 1931 in the Germanischer Lloyd Rules for Surveying and Testing of Plywood for Aircraft and MIL-P-607, the latter of which calls for shear testing after immersion in boiling water for three hours to verify the adhesive qualities between the plies meets specifications. Aircraft grade plywood is made from three or more plies of birch, as thin as {{convert|1/64|in|mm|order=flip}} thick in total, and is extremely strong and light. 

Howard Hughes' [[H-4 Hercules]] was constructed of plywood. The plane was built by the [[Hughes Aircraft Company]] employing a plywood-and-resin [[Duramold]] process.<ref>Winchester, Jim. "Hughes H-4 'Spruce Goose'." ''Concept Aircraft: Prototypes, X-Planes and Experimental Aircraft''. Kent, UK: Grange Books plc., 2005. {{ISBN|978-1-59223-480-6}} p. 113.</ref> The specialized wood veneer was made by Roddis Manufacturing in [[Marshfield, Wisconsin]].<ref>[http://www.marshfieldnewsherald.com/article/20131023/MNH01/310230453/Marshfield-women-recall-building-engineering-marvels-skies?nclick_check=1 Marshfield women recall building engineering marvels of the skies] {{webarchive|url=https://web.archive.org/web/20141217024344/http://www.marshfieldnewsherald.com/article/20131023/MNH01/310230453/Marshfield-women-recall-building-engineering-marvels-skies?nclick_check=1 |date=2014-12-17 }}, Marshfield News Herald</ref>