Exhaust Tubes

Exhaust tubes (foot valves, blow tubes) are an important part of the drill bit. Expensive downtime can be reduced by having some on hand. Nothing like having a little piece of plastic ruin your day. A lot of bit manufacturers have their own specifications for fitting the exhaust tube into their bit, but many have standardized on QL, IR, and Mission style tubes. It is always best if you know the manufacturer of the bit so you can get the correct tube. We need to know the ID and depth to shoulder of the hole in the bit.

To remove a broken exhaust tube you can either cut it with a reciprocating saw and pry it out or you can burn it out with an acytelene torch or blowtorch. Lay the bit on its side, get the tube burning, and then let it burn itself out. Obviously if you are using this method, fire prevention measures must be taken.

Exhaust Tube for	OAL	Upper OD	Lower OD	Ridge to Base
IR 3.5 shank bits	3.800"	0.970"	1.030"	1.574"
IR 340 shank bits - Heavy Duty	3.715"	1.050"	1.245"	1.405"
IR 350 shank bits - Heavy Duty	4.505"	1.375"	1.550"	1.842"
IR 360 shank bits - Heavy Duty	3.795"	1.500"	1.735"	1.840"
IR 380 shank bits	4.985"	1.995"	2.200"	2.890"
IR 380 shank bits - Heavy Duty	4.990"	1.995"	2.200"	2.890"
QL6 shank bits	4.262"	1.815"	1.835"	1.500"
QL8 shank bits	4.450"	2.148"	2.220"	1.550"

All dimensions are approximate.

Exhaust Tube for	OAL	Upper OD	Rib OD	Beginning of Top Rib to Base
SD3 shank bits	3.500"	0.868"	0.970"	1.538"
SD4 shank bits	3.505"	1.028"	1.115"	1.535"
SD5 shank bits	3.508"	1.248"	1.335"	1.505"
SD6 shank bits	3.508"	1.435"	1.521"	1.515"
SD8 shank bits	3.603"	1.630"	1.705"	1.540"
SD10 shank bits	3.650"	2.202"	2.286"	1.545"
SD12 shank bits	3.710"	2.485"	2.585"	2.060"

All dimensions are approximate.