Hi , i have recently changed the pcd of some hubs and one of the original holes needed welding up so i put in a bit of mild steel and mig'd it up.
I then put it into sand to cool as slow as possible, ground the flash off, started to drill it with a 3mm presto hss drill and no prob ( i need a 14 mm hole to put a stud in it)
I'm using a large pillar drill
I have got to 6 mm wide and it's just a pain! I have to sharpen the drill every 5mm drilling, drill bit is cooled and sharp ( job is only 20mm deep)
Tried slow and fast speed
Tried going bigger, bit just chatters
GRRRRRRRR
Anyone help
I then put it into sand to cool as slow as possible, ground the flash off, started to drill it with a 3mm presto hss drill and no prob ( i need a 14 mm hole to put a stud in it)
I'm using a large pillar drill
I have got to 6 mm wide and it's just a pain! I have to sharpen the drill every 5mm drilling, drill bit is cooled and sharp ( job is only 20mm deep)
Tried slow and fast speed
Tried going bigger, bit just chatters
GRRRRRRRR
Anyone help