"FOUR COUNTEREDBORED HOLES,COUNTERBORE 0.250 IN. DIA BY 0.180 IN. DEEP,0.145 IN. MIN AND 0.150 IN. MAX DIA THRU ON 1.840 IN. BY 1.840 IN. MTG CENTER; FOUR HOLES THD,0.086-56 UNC-2B THRU ON 1.240 IN. BY 1.240 IN. MTG CENTER"
MDCL
MATERIAL DOCUMENT AND CLASSIFICATION
"QQ-A-225/6 FED SPEC 1ST MATERIAL RESPONSE OR QQ-A-200/3, 2034-T351 FED SPEC 2ND MATERIAL RESPONSE"