Explanation: Chisel: mortise; tenon: tenon. Square tenon does not fit gouge. Metaphor out of tune, can not be matched. Source: Warring States Chu Song "Nine identified" gouge the square tenon Come, I know these disagreements and hard into the solid. " Examples: However, miscellaneous take "ram" "Gu Liang," to address "Tso", which was to crown two-sandals will be integrated hemp silk, ~, which may call into? (Tang Kong Yingda "Spring and Autumn just order")
Round mortise and tenon square
Round mortise and tenon square. Yu is not congenial cooperation between the two. Tang Standard Interpretation "<Spring and Autumn just> order": "This is the highest pair of sandals to be fully mechanized linen silk, square chisel round tenon, it can enter into?" Tang Quan, "<Lu Xuan Gonghan Court Sets> order": "square chisel round tenon, good work is nothing to measure clever mind. "see" square peg round hole. "