A blueprint dimension is written as 7.439 inches plus .007 inches minus .003 inches. What is the minimum acceptable size?

A blueprint dimension is written as 7.439 inches plus .007 inches minus .003 inches. What is the minimum acceptable size?

• A. 7.436
• B. 7.446
• C. 7.439
• D. 7.442

Answer: (A)

When a dimension shows plus and minus tolerances, it defines an allowable range around the nominal size. The notation 7.439 +0.007 −0.003 means the size can vary from the nominal by up to +0.007 inches or −0.003 inches. So the smallest acceptable size is the nominal minus the negative tolerance: 7.439 − 0.003 = 7.436 inches. The largest acceptable size is 7.439 + 0.007 = 7.446 inches, and anything in between is fine. Therefore, the minimum allowable size is 7.436 inches.

When a dimension shows plus and minus tolerances, it defines an allowable range around the nominal size. The notation 7.439 +0.007 −0.003 means the size can vary from the nominal by up to +0.007 inches or −0.003 inches. So the smallest acceptable size is the nominal minus the negative tolerance: 7.439 − 0.003 = 7.436 inches. The largest acceptable size is 7.439 + 0.007 = 7.446 inches, and anything in between is fine. Therefore, the minimum allowable size is 7.436 inches.