Item Number

When I first started entering purchases of beading supplies, I put the manufacturer's number in both the Item Name and Manufacturer Part Number.  Now I have far too many items and find it cumbersome to list each item I use in a build.  It would be great if I were just entering the number of beads and findings.  Is there a way to change all of the old Item Names to either Beads or Findings without changing anything like the cost of purchase, etc?  When I tried to change the Item Name on an individual item, it asked if I wanted to merge and since I'm not sure what happens in the case, I cancelled it. I'd appreciate any pointers on how I can make this happen without affecting anything in QB except the Item Name. Thanks!