Bulkhead Size Vs Hole Size

privitor · 03/24/2012, 05:10 PM

Bulkhead Size Vs Hole Size

OK im having a problem with bulkhead size vs hole size

I have a (1½" 38mm) holes saw and a 1" bulk head

Upon doing research, most places say i need a 1 3/4" hole for a 1" bulkhead

My problem is why do i need a hole so big? The bulkhead will technically fit in a 1" ½ hole almost perfectly so why is it recommended that i drill almost a ¼" bigger hole?

could i get away with just drilling the 1½" hole for my 1" bulk head as long as it fits the hole??

hope this makes sense?

James77 · 03/24/2012, 05:24 PM

If it fits the hole, you are fine. Not sure why the discrepancy, probably due to varying thicknesses amongst brands.

ReLPSef · 03/24/2012, 05:33 PM

Also, make sure the rubber washer is completely around the hole and not overlapping.

bnumair · 03/24/2012, 06:21 PM

in my opnion the hole should be just big enough to fit the bulkhead right through it without forcing twisting or pushing it. bulkhead should just drop right in.

shifty51008 · 03/24/2012, 07:19 PM

the diffrence comes with diff. sch bulkheads.

a 1” ABS Bulkhead takes a 42mm hole
a 1” SCH 80 Bulkhead takes a 48mm hole

diffrend brand bulkheads will take diff. hole sizes

privitor · 03/24/2012, 08:53 PM

Quote:

Originally Posted by shifty51008

the diffrence comes with diff. sch bulkheads.

a 1” ABS Bulkhead takes a 42mm hole
a 1” SCH 80 Bulkhead takes a 48mm hole

thats my point it says use a 42mm but if i use a 38mm hole saw for a 1" bulkhead it might be a little snug but i think it would still fit.

my other options would be buy a one size larger bit or reduce the bulkhead to 3/4" but i would like to use what i got if possible.

shifty51008 · 03/24/2012, 10:19 PM

I would say if the bulkhead slides right through you will be fine

privitor · 03/24/2012, 11:38 PM

what i did was took a tape measure and measured the nut that goes on the 1"bulkhead and it measured just over 1 ¼" which means in in theory it should have no problem fitting in 1½ hole right? then to double check i slipped the bulkhead into the inside of the 1½ bit and it fit with no problems over the threads

this is why i was led to belive the 1" would fit in a 1½ hold... But i could be wrong and i challenge you to convince me that i am....

shifty51008 · 03/25/2012, 12:35 AM

nope your right, you did the same thing I do by putting the bulkhead inside the bit, if it fits with not to much wobble I go with it and it has worked fine so far.

privitor · 03/30/2012, 03:16 PM

Ok so to settle this small debate! I drilled my tank today with my 1½" saw and my 1' bulk head fit almost perfectly! I think if i would have use 1 3/4" saw it would have been too big of a hole IMO. The 1½" hole was big enough with enough space for the bulkhead to fit loosely and the oring thing fits over it exact too.

03/24/2012, 05:10 PM	#1
privitor TC.ARK Join Date: Mar 2008 Location: Palm City, Florida Posts: 229	Bulkhead Size Vs Hole Size Bulkhead Size Vs Hole Size OK im having a problem with bulkhead size vs hole size I have a (1½" 38mm) holes saw and a 1" bulk head Upon doing research, most places say i need a 1 3/4" hole for a 1" bulkhead My problem is why do i need a hole so big? The bulkhead will technically fit in a 1" ½ hole almost perfectly so why is it recommended that i drill almost a ¼" bigger hole? could i get away with just drilling the 1½" hole for my 1" bulk head as long as it fits the hole?? hope this makes sense?

03/24/2012, 05:24 PM	#2
James77 Registered Member Join Date: Aug 2005 Location: Rhode Island Posts: 8,158	If it fits the hole, you are fine. Not sure why the discrepancy, probably due to varying thicknesses amongst brands. __________________ Jim Current Tank Info: 120g Mixed Reef and 75g Freshwater

03/24/2012, 06:21 PM	#4
bnumair Dr. Reef at ur service Join Date: May 2009 Location: Tulsa, Ok, USA Posts: 7,751 Blog Entries: 15	in my opnion the hole should be just big enough to fit the bulkhead right through it without forcing twisting or pushing it. bulkhead should just drop right in. __________________ Water Quality: NO3 0,Phos 0,Cal 440,Alk 7.5,Mag 1300 "Reef Fast, You Crash, Reef Slow, You Pass" Mike's Reef 3:16 Current Tank Info: 350g DT,95g sump, 50g Frag tank, 4800gph return 4x Sea swirls. 6x AI Vega Color. 200# Pukani rock, dual recirculating skimmer, Biopellet, GFO Carbon rx's, Cal rx. Closed loop. 1.5hp chiller, genesis renew. Apex & RKE

03/24/2012, 07:19 PM	#5
shifty51008 12-5 Chiefs record Join Date: Mar 2010 Location: NW Iowa Posts: 10,134	the diffrence comes with diff. sch bulkheads. a 1” ABS Bulkhead takes a 42mm hole a 1” SCH 80 Bulkhead takes a 48mm hole diffrend brand bulkheads will take diff. hole sizes __________________ 75 gal. mixed DT, 100 gal. sump, 50 gal. fuge, Clownfish breeder

03/24/2012, 10:19 PM	#7
shifty51008 12-5 Chiefs record Join Date: Mar 2010 Location: NW Iowa Posts: 10,134	I would say if the bulkhead slides right through you will be fine __________________ 75 gal. mixed DT, 100 gal. sump, 50 gal. fuge, Clownfish breeder

03/24/2012, 05:33 PM	#3
ReLPSef Registered Member Join Date: Jan 2012 Location: Florida Posts: 169	Also, make sure the rubber washer is completely around the hole and not overlapping.

03/24/2012, 11:38 PM	#8
privitor TC.ARK Join Date: Mar 2008 Location: Palm City, Florida Posts: 229	what i did was took a tape measure and measured the nut that goes on the 1"bulkhead and it measured just over 1 ¼" which means in in theory it should have no problem fitting in 1½ hole right? then to double check i slipped the bulkhead into the inside of the 1½ bit and it fit with no problems over the threads this is why i was led to belive the 1" would fit in a 1½ hold... But i could be wrong and i challenge you to convince me that i am....

03/25/2012, 12:35 AM	#9
shifty51008 12-5 Chiefs record Join Date: Mar 2010 Location: NW Iowa Posts: 10,134	nope your right, you did the same thing I do by putting the bulkhead inside the bit, if it fits with not to much wobble I go with it and it has worked fine so far. __________________ 75 gal. mixed DT, 100 gal. sump, 50 gal. fuge, Clownfish breeder

03/30/2012, 03:16 PM	#10
privitor TC.ARK Join Date: Mar 2008 Location: Palm City, Florida Posts: 229	Ok so to settle this small debate! I drilled my tank today with my 1½" saw and my 1' bulk head fit almost perfectly! I think if i would have use 1 3/4" saw it would have been too big of a hole IMO. The 1½" hole was big enough with enough space for the bulkhead to fit loosely and the oring thing fits over it exact too. __________________ Hey Mr Grumpy Gills,You know what you gotta do when life gets you down? Just keep swimming, Just keep swimming, Just keep swimming swimming swimming What do we do we swim, swim, swim!!!