Goldfish Development. Baby goldfish are born much darker than they will be as adults. This may be because dark colors helps these small, vulnerable fish escape the attention of predators. With proper husbandry, the fish gradually change color and develop orange or gold scales. Fancy goldfish may develop color patterns including white patches.
Posts: 1,396. Re: Bits for hand drilling hardened steel. If you want to experiment with carbide drilling on the cheap, buy a carbide tipped masonry drill bit set. They are about $20 a set new, but I find them at garage sales for about $1 for the set all the time and that's why I use them.
Drill bits that can drill through concrete are called masonry bits. They are also good for drilling through brick and stone. Drill bits with a tungsten carbide tip are the strongest; when it comes to solid concrete, the sharper the better. Masonry bits cut holes through concrete in two steps.