Gluing Steel Threaded Inserts in Pri-Drilledhole in Granite stone

There is great product J.B. Weld available from most good hard ware outlets.

JB weld Co. PO Box 483 Sulpher Springs Texas 75483

JB Weld UK Ltd. Unit 3,Polygon Business Centre, Blackthorn Rd, Colnbrook, Slough Berkshire SL3 0TP.

The best I can do for now.

Hi !!

Thanks for your very quick response.

May I have phone No / fax no or website of this company ? My son is doing Undergrade ( Elect Engg ) at UOH I can ask hime to visit this company and geta few sample quantity and courear to me.

What is the product code or Product name ?

Thanks once again for your valuable input.

I would like to have more inputs and other addresses in case I do not get the right thing for my application.

Do you have any idea about clearance to be maintained for optimum bonding stregth

Udayan Patel

udayan121049@yahoo.co.in

JB weld will suit all your requirements it is as strong as steel when set and can be fully machined or hand finished; a bond line of just a few thou to a 1/2 " will hold it is an industrial type adhesive in a two part epoxy set. It ends up a dull grey finish.

Please see the following manufactures for structural anchor epoxies:

Hilti (Available World Wide) Chemical Anchor Epoxies and Mechanical type threaded inserts.

Rammset (Redhead G5 is very good 15 minute working time in high temperatures cures within 2hrs)

Epcon (Identical to Redhead)

See manufactures information for hole sizes it is usually 3mm (1/8") larger that the dowel/anchor/rod. There is good technical support on these products, that if nothing else will be a good guide for you. For bulk applications the pneumatic guns are excellent.

There are many other alternatives such a plumbers welds, grip fill liquid nails etc. But they are not engineered for such applications. Although 30Nm is not a high torque setting it does not indicate the tensile force due to loading, that will cause pull out. I assume as you are selecting M8 brass inserts the application does not require a high tensile or shear strength. If this is not a load bearing application almost any epoxy or polyurethane adhesive would suffice, from JB to Araldite, even single part types will do such as grip fill or liquid nails (Look at Scotch 3M, Unibond, BASF or for other references see builders suppliers such as www.screwfix.co.uk and www.acehardware.com).

Loctite may have a product that will suit your needs. Henkel Corp.1001 Trout Brook Crossing, Rocky Hill, CT 06067 Phone:1-800-563-8483, www.loctite.com

Loctite is the way to go.They offer many different componations of epoxy.Have had great sucess with there products.

I would suggest 3M 5200 polyurethane adhesive. The only problem might be that this can take from 24 hours to 8 days to set, depending on the formulation.

I don't know if it would meet your torque requirements. It might be better to use a combination of the polyurethane and a mechanical fastener.

Just go with the JB weld you will thank me for it. It is easy to apply and sets fairly fast if heated some it sets even faster. A little goes a long way.

The Hilti products are specifically designed, engineered, and tested for this type of application. I first started using their products over 20 years ago when they came out. They work in concrete, stone, brick, etc.

Some of the other adhesives may appear to be strong, but have not been tested to failure. When done in accordance with the manufacturer's recommendations, we were unable to pull out 1/2" diameter 304 stainless threaded rods. On a test of 10 rods with hydraulic jacks, 9 of them necked and failed in tension, and the 10th one pulled a concrete cone with it. (The concrete failed in tension)

If you are hanging or suspending anything, and don't want it to fall, go with a product that is "purpose" designed.

Eric C. Pettit, P.Eng. UMA Engineering Ltd. " Pity the man who has ceased learning, for he is surely dead. " -- Unknown --

Eric, is correct, the engineered chemical anchor epoxies are superior. I have even witnessed incorrectly installed anchors; usually ones where the hole has not been blown out with and air line or brushed with the small cylindrical brush, hold until the threaded rod failed, even though the bond between the concrete and epoxy has failed because the rod would rotate when the nut was tightened before testing. This was due to the hole not being perfectly cylindrical creating a wedge effect (The QC still rejected it and the company had to cut out a section of ring beam and re-cast it). As stated before they are engineered for the job and designed to adhere to concrete, stone and brick. Any multi purpose product should be for non-load bearing only, such as small plaque mounting or ornamental fixing.

Hilti is the market leader but is the most expensive and most widely available the standard is HY500, the HY150 is a real pain in hot climates it is very thick and grainy, and the compression force from screwing a rod in will often cause the epoxy to set before the rod can be inserted fully, even in shallow holes.

The Redhead G5 is half the price has the same strength properties, and is much better in hotter climates. I recently used this for column anchoring on 2400 individual anchors and believe it is better than the Hilti due to its working and setting times. It produced the same results to hilti's when tested as well. The key is to follow the manufactures specifications for hole size, location from edge faces, cleaning, epoxy application and required volume.

Hilti's HVU capsule is good for small quantites and minimises wastage in such applications.

Hey man, I'd see what everyone else has been using for the last 20+ years if this is for granite surface plates that are used for layout work.
(Like in a Metrology lab, machine shop or plant floor)

In that case thermally stable (very little dimensional movement) will probably be the issue not pull out strenght unless your fixturing something heavy and off balance.

Also I'd consider strong inserts (stainless) and weak bolts (Grade 2) because its far better to strip the bolt than the insert. I use SS because as a former Machinist I know how NOT to stip bolts but it's a different case if you have an operator on a CMM!

L8R,
Mark

Hi !!

Thanks to all for their inputs.

I would request all giving nputs to please mention the Website of these companies and if possible, their address & Phone / Fax No to enable me to establish contact with the companies supplying Epoxy. I have visited website of JB Weld and would like to probe more about other products before finally using for my application.

These inserts are laid on the Granite Table using a template for locational accuracy and glued. Linera Motion Rails are bolted on top of table and inserts are used to bolt the rail on Granite. Customers are very fussy about the strength of epoxy bond and it should not pull out under torque test. In some cases Torque is applied for 30 days to see that Inserts does not pull out. For this a test rig is prepared and any amount of pull out is checked on Dial Gauge and readings are observed for 30 days while inserts are under constantly loaded condition for 3o days by torque wrench in postion and pull out up to 20 microns only is allowed

In the past we used Araldite AW 138 + HV998 two part epoxy suuplied by Subsidary of Huntsman Advanced Material LLCof USA , which did not give good result and hence we are looking for a better product for our application.These Tables are used for CMMs and also for gantry stages

Can Anyone sujjest What should be the optimum gap between the inserts and Granite wall. ? I feel higher gaps( more than 0.8 mm ) would result in to poor strength of the bond.

Any suggestions ? Thanks in anticipation

Udayan Patel

udayan121049@yahoo.co.in

JB Well was used to repair a prop shaft on a large comercial tractor after the shaft failed due to a faulty repair weld it the lasted for the life of the machine several years of constant wear and tear. The join never failed.

JB Weld was once spotted coming out of the 6th form girl's dormitory, of the Badminton School for Girls, at midnight with a ¼ full bottle of Pimms.

Surely not with JB's reputation.

www.google.com for all searches

Enter www.hilti.com into your explorer bar and you will find enlightenment. They have a full array of table for just such applications, note you will have to register, which is free in-order to access technical data. If customers are fussy use the best which is engineered for the jobs, where torque and pull out is a requirement for the life of the structure. They are specifically designed to adhere to hard stone and concrete

0.75mm is the recommended clearance either side for an 8mm stud but your insert would be bigger than 8mm to accept an M8 bolt. In the past I have drilled and tapped larger threaded studs to make a threaded insert, this would give the anchorage required into the epoxy.

Note: Bolt torques are not an indication of pull-out force, this is because of friction between the threads. In structural engineering many governing bodies will now only except bolt tension meter readings when accepting bolted connection QC reports.

Thanks a lot for giving links of Website.

Clearance suggested appears too large. I was told that for good bond strength Clearance should be as low as possible. but no one has given correct value,however I have seen the specs sheet of Huntsman Advanced material for Araldite AV 138 M & hardner HV 998 which says clearance of 0.05 mm to 0.1 mm wouldgive best results but this is a very general statement. Problem is when we drill in Granite using diamond core drill maintaining accurate dimensions of hole size to ).05 mm to 0.1 mm is not that simple.

For M-8 Thread OD of inserts is 20 mm and insert length is 25 mm and we test is @ 30 Nm torque for checking Pull out.

Will providing Knurled finish on OD of Insert help improving Bond strength ? When it is knurled surface area increases but the gap between the Granite Wall and depreseed portion ofKnurled surface also increases thereby creating more clearance at selectve places.

I will visit site of Hilti and see if they have anything to offer for our application.

Thanks once again to all. Shall revert back soon after visiting site of Hilti

Udayan

In site applications for anchor epoxies such as Hilti, Carbide tiped drills are the norm and the common equipment is a hilti electric hammer drill. Where tolerances of 0.1mm would never be expected, may be tolerances of 0.5 to 1mm if you are good, and the epoxies have no problem.

As for Knurling, it is probably as we say 6 of one half a dozen of the other. As part of the surface is depressed another part has to distorted either outwards or the insert will bow due to elongation. A bowed shape (Larger end diameters, with diameter decreasing towards the middle) would create a wedge type affect. Instead of knurling why not cut a thread in the outer surface; threads are proven to be a good locking mechanism in anchor epoxy. As anchor epoxies are not designed to bond with metal but rather with the concrete or stone, the thread is a mechanical locking device with the epoxies bigger bond strength between its own particles.