b00stedsi

what is the best way to go about this? for an egt probe?


[Modified by turkish, 9:26 AM 7/28/2002]

PrecisionH23a

get a drillbit that is made for drilling cast iron and drill a hole. then thread the hole to the proper pitch to install the probe. wahla... done.

BigMoose

Ditto. Cast Iron will grab a bit ground to optimum steel angles. I don't have my reference here, but I had to redrill 30 deep holes in my backhoe rearend/differential from 3/8 to 1/2 inch studs. The first hole I did with a steel bit and it scared the daylights out of me. No control it grabbed, almost broke my wrist with the high power d handle drill I was using, and by the grace of God I did not break the 1/2 inch drill bit off. I went and got my Machinery's Handbook, reground the drill and the other 29 holes drilled like butter.


If my memory is correct, cast wants a flatter angle (less pointy) and less back relief, but check first, I am not sure of the exact angles without the handbook.

Regards,
BigMoose


[Modified by BigMoose, 10:21 PM 7/28/2002]

Smashback

Get a regular drill bit. It's only one small hole. Even if you wreck the bit, who cares unless you're going to do it over and over. I didn't have any probs.

Mase

cast iron is very soft. alot easier drillin and tappin the cast iron, versus that damn steel downpipe.

JMinSi2000

I drilled a hole and had someone weld a bung on mine.

BigMoose

Thats what I get for trying to post quickly before Church this morning. Of course these guys are right, the manifold is only 2mm thick, so any drill will go thru, the holes I was drilling were an inch deep, the grabbed like a SOB. Cast drills like butter.

To make up, here is a little info on drill point angles for those interested:

118-DEGREE DRILL POINT: 118 degrees is the standard general purpose or manufacturers' standard. It is used for a high and wide variation of materials and job conditions.

135-DEGREE DRILL POINT: This point is frequently preferred for hard and tough materials such as high alloy steels. Increasing the point angle (from 118 degrees) reduces the length of the lips. The result is a reduction in the driving torque required to drill these materials. The feed pressures are increased. Reducing the lip relief angle strengthens the lip.

90-DEGREE DRILL POINT: Use a 90-degree drill bit is for aluminum, plastic, wood, and some cast iron. It reduces feed pressures and permits higher feed rates. Many soft and low strength materials, such as some cast irons, aluminum, plastic and wood can be drilled more efficiently with a reduced point angle. Although this change reduces the effective rake angle of the cutting edge (lip) and the length of the lip is increased, the driving torque required to drill these materials usually remains within acceptable limits. The reduced feed pressures and the increased lip relief angle frequently permit higher feed rates.


SPLIT POINTS: Used for self-centering and lowering thrust. Lowering thrust will reduce the risk of broken drills and extend drill life. Split points are excellent for CNC equipment.

Regards,
BigMoose

bigTom

use a drill with a carbide bit... ull be happy u did... makes life much easier