hard maple

基本解釋

Press dried rotary cut American Hard Maple veneer, AB grade.
機械干燥旋切美國硬楓木單板AB級。
Soft maple strength than hard maple low about 25%, On colour is hard maple dim, burnish is no hard maple bright;
軟楓的強度要比硬楓低25%左右；色彩上較硬楓暗淡，光澤沒有硬楓亮；
Exhibit: american hardwood lumber and floorings. species include red oak white oak ash hard maple soft maple hickory cherry basswood beech birch curly soft maple butternut white pine etc.
展品：北美硬木板材，地板等。品種包括紅橡，白橡，水曲柳，硬楓，軟楓，山核桃木，櫻桃木，椴木，山毛櫸，樺木，波紋軟楓，白胡桃，白松木等。

They seem like the hard rock maple trees often found in that area, nothing can make them move.

It's most common in hard maple, but also occurs in birch, ash and, in rare cases, black walnut.
NPR: Excerpt: 'A Splintered History Of Wood'