Any Tips For Drilling A 1mm Hole In A Grubscrew?

[stolly]

As the title says, anyone got any tips for drilling a 1mm hole through a grubscrew? The only grubscrews I can find are hardened and are bloody tough to drill through - using a 1mm drill isn't helping, just keep snapping them off.

I have made a tool that the grubscrew screws into wihch then slots into another piece on the benchdrill, so it is dead centre and not moving at all.

Have also tried heating them up and then chucking them in a bucket of water which made it a little easier, but still hard.

Any hints greatly appreciated.

Cheers

[Craved]

high speed

low pressure

plenty of cutting oil

[StealthX]

high speed

low pressure

plenty of cutting oil

this.

[BundyBear]

As the title says, anyone got any tips for drilling a 1mm hole through a grubscrew? The only grubscrews I can find are hardened and are bloody tough to drill through - using a 1mm drill isn't helping, just keep snapping them off.

I have made a tool that the grubscrew screws into wihch then slots into another piece on the benchdrill, so it is dead centre and not moving at all.

Have also tried heating them up and then chucking them in a bucket of water which made it a little easier, but still hard.

Any hints greatly appreciated.

Cheers

maybe alternate between heating the little bugger, then drill till it cools, and repeat ??? maybe

how are you heating them?? gas Axe or blowtorch? white hot or just hot

[iplen]

Use a 1mm drill bit

[Duncan]

and very important....us a drill press of course. Otherwise many broken drills lie ahead in your future

[Duncan]

why btw?

[stolly]

why btw?

-Drilling and tapping a thread into a nipple that screws into a hydraulic cylinder, the grubscrew screws into the nipple and acts as a restrictor for the oil flow so that the ram doesn't open to quickly.

-Using a drill press but still breaking a shitload of drills.

[32_Dave]

most likely be a high tensile steel, which is a flamin mongrel to drill or cut. try find a 1mm high speed bit made by sutton or p&n, should go through it easy enough. and make sure your drill bit is installed in the chuck properly. make sure its clamped on the smooth surface. rookie error seen many a bits snap incorrectly installed in the chuck.

[Craig SLO33]

Just a thought. i dont know what size your grub screw is but what about something like a jet from a holley carby with a small jet size.. do you know what i mean ?

[260tech]

-Drilling and tapping a thread into a nipple that screws into a hydraulic cylinder, the grubscrew screws into the nipple and acts as a restrictor for the oil flow so that the ram doesn't open to quickly.

-Using a drill press but still breaking a shitload of drills.

Hi there, most quality cylinders have speed restrictors built in. Maybe source around for one that is more applicable for your purpose, (Suppliers/users like SMC, Pirtek, Fluidline etc.,) else get some titanium drill bits, a variable speed drill/lathe whatever that has minimal head/chuck slack & use that really nasty green stuff.....Trafelex as your cutting lube. Else stick a few plugs of base nipple thread size in an envelope & take to your local machine shop, along with your preferred final drill size.

Or; get yourself a couple of Whitey/Hoke needle valves & pipe them into the "extend/retract" hyd lines running to the cylinder, if your application allows the luxury of course.

Cheers GW

[stolly]

Hi there, most quality cylinders have speed restrictors built in. Maybe source around for one that is more applicable for your purpose, (Suppliers/users like SMC, Pirtek, Fluidline etc.,) else get some titanium drill bits, a variable speed drill/lathe whatever that has minimal head/chuck slack & use that really nasty green stuff.....Trafelex as your cutting lube. Else stick a few plugs of base nipple thread size in an envelope & take to your local machine shop, along with your preferred final drill size.

Or; get yourself a couple of Whitey/Hoke needle valves & pipe them into the "extend/retract" hyd lines running to the cylinder, if your application allows the luxury of course.

Cheers GW

-thanks for that, we use Vickers and Southcott cylinders have never seen them with a speed restrictor built in. Do you mean built into the nipple that screws into the inlet and outlet ports of the cylinder?

All our rams turn up with a female thread with a plastic plug in it. We screw a C3-0909 nipple into them and it is this nipple that we are tapping an internal thread into that a 3/8" grubscrew screws into. Don't want to use a needle valve as I want it to be 'set and forget' and not give clients the option of adjusting the extend/retract speed, with the internal grubscrew no-one will know it's there so won't be likely to fiddle with it.

I'll try a titanium drill tomorrow and try and grab some of that lube. Using Rocol at the moment which is generally pretty good.

[stolly]

Just a thought. i dont know what size your grub screw is but what about something like a jet from a holley carby with a small jet size.. do you know what i mean ?

Yeah, know exactly what you mean. Have been thinking of trying something similar. Only problem is the thread size is 3/8" so the carby jet won't do. Grubscrew is the best I can think of. Also has to be able to be screwed in with an allen key.

[260tech]

-thanks for that, we use Vickers and Southcott cylinders have never seen them with a speed restrictor built in. Do you mean built into the nipple that screws into the inlet and outlet ports of the cylinder?

All our rams turn up with a female thread with a plastic plug in it. We screw a C3-0909 nipple into them and it is this nipple that we are tapping an internal thread into that a 3/8" grubscrew screws into. Don't want to use a needle valve as I want it to be 'set and forget' and not give clients the option of adjusting the extend/retract speed, with the internal grubscrew no-one will know it's there so won't be likely to fiddle with it.

I'll try a titanium drill tomorrow and try and grab some of that lube. Using Rocol at the moment which is generally pretty good.

Rocol cutting oil should be satisfactory, I like that stuff, had good results. I only mentioned the green stuff as that is the meanest gear I have used, it allowed me to drill through rig drill rods ~ very hard material, (with ordinary high speed drills). Just need to find optimum drill speed with drill of either drill material/cutting fluid that will hack it.

Cylinder with the restrictors I refer to are not "set & forget" as the restrictors are readily accessible, installed in the "end blocks", adjacent drive-pipe port entry for ext/ret. Need screwdriver/allen key to adjust but still not "tamper-proof". Maybe your cylinder of choice is mostly used in applications where rate control is by external proportional speed valves? Dunno.

Cheers GW

[crack]

depending on how long the grub screw is, drill into it with a 1/8 drill leaving approx. 2mm to go then use 1mm drill for the remainder. the 1/8 drill is used purely because it is stronger. rocol or trefalex will do. my 2 cents.

[Cartman]

i think its a cobolt drill bit you need for high tensial

[XRATED]

water jet? if you get can get somone to do such a small job. I've had parts cut to .75mm tolerance...

OR

Manufacure your own sloted set screw from mild steel. If its a hydralic application, mild should last a long time.

Justin

[naga]

does it have to be 1mm all the way through? if not ideally you'd start with a short starter drill or at least something bigger and stiffer. after you start should be much easier to drill the rest.

[aerofocker]

does it have to be 1mm all the way through? if not ideally you'd start with a short starter drill or at least something bigger and stiffer. after you start should be much easier to drill the rest.

anneal the steel grub screw by heating it to cherry red and allowing to cool naturally,use the fastest speed on the drill,unfortunately to stop the bit from breaking you have to use momentum,lots of cutting fluid because the speed generates heat and blunts the bit

[naga]

found this recently:

http://vik-olliver.blogspot.com/2010/02/dr...own-middle.html