Chevrolet 1988 Light Duty Truck Repair Manual page 12

OA-8 GENERAL INFORMATION
Passenger Van
Cargo Van
Figure 12— M Models
1. Grade 2 (GM 200-M)
2. Grade 5 (GM 280-M)
3. Grade 7 (GM 290-M)
4. Grade 8 (GM 300-M)
5. M a n u fa ctu re r's Id e n tific a tio n
6. N ut S trength Id e n tific a tio n
7. Id e n tific a tio n M arks (Posidriv Screw Head)
Figure 13— Bolt and Nut Identification
1. C ustom ary B o lt— 1 /4-20
2. M etric B o lt— M6.0x1
A. 1 /4-inch
B. 6 mm
C. 20 Threads Per Inch
D. 1 Thread Per M illim e te r
B-09261
F-00695
Figure 15— Six Lobed Socket Head Fasteners
(25.4 Threads Per Inch)
Figure 14— Thread Notation
F-00705