Rawlplugs (Size No. 3 and 6) are packed with screws specially made threaded right up to the head, to i ncrease grip. The longer length of thread gives a greater hold, and it also saves the necessity of countersinking the Rawlplug.

Rawlplug Tools

The Rawlplug Tool should be kept sharp. It can be resharpened in the ordinary way on a grindstone or paving stone.

To extract the Bit from the Toolholder, use the Rawlplug ejector or a nail or anything suitably pointed ; push it into the ejector hole and force out the Bit, or else use a vice.

These new-size Rawlplugs are designed for use with any size or length of gimlet-pointed coach screw from 3/8in. to 5/8in. (diameter), and are being rapidly adopted by the largest contractors, electrical and engineering concerns all over the country.

The new sizes of Rawlplugs (Nos. 22-28) together with the standard sizes (Nos. 3-20) now give a complete range of Rawlplugs suitable for every weight of fixture.

Actual tests have proved that one of the large-sized Rawlplugs (No. 28 4in.) will withstand a direct strain of over four tons in concrete.

Foundation Bolts. The Rawlplug Bolt Anchor is a new invention which enables exceedingly strong fixings to be obtained for bolts in practically any kind of really hard material, such as rock, brick, concrete, etc. It is all metal, and therefore is unaffected by atmospheric conditions. Thus, it can be fixed in water should this be necessary, this feature being a great asset where fixings in harbours, quays, railways, etc., have to be made. In fact, for all outdoor constructional work of a really heavy nature, it is ideal.

The Rawlplug Bolt Anchor is constructed from specially chilled iron in combination with lead, and is so formed that when fixed in position upon the head of a bolt, the chilled iron section forms a series of struts between the Bolt-head and the walls of the hole, the result is that it is impossible to withdraw the bolt until the walls of the hole itself actually breakaway, or the bolt fractures.

Reference to Fig. 175 will emphasise the simplicity of construction of the Rawlplug Bolt Anchor, the lower end of which consists of a truncated cone of chilled iron, attached to a cylinder of lead. The iron cone is divided into segments, which are shaped in such a way that the edges are sharp at their greatest diameter.

The method of use is, first to prepare a hole with the aid of a Rawlplug Tool, then place a bolt in the hole, head foremost, place a thick iron washer on the bolt, pressing it snugly against the bolt-head, and, finally, follow with the Rawlplug Bolt Anchor, being careful to place cone-shape head foremost, so that when in position it rests against the washer.

Everything is now ready for caulking which should be carried out with the aid of the Rawlplug caulking tool and a heavy ham-mer.

The action of caulking has the effect of not only wedging the lead firmly against the bolt and the walls of the hole, but also of causing the hard iron cone to fracture at the segments and force the cutting edges into the wall of the hole (see Fig. 175) ; these segments become more firmly embedded the more the bolt is stressed.

Fig. 175.

The Rawlplug Bolt Anchor is made in sizes ranging from 3/8in. to 11/4in., and the depth to which they should be fixed varies according to the kind of material in which the fixing is to be made. Should the material be hard and .unyielding a hole of lesser depth is required than when fixing in weak concrete. In good concrete for small sizes a depth of about 4in. is sufficient, whereas a depth of from Pin. to 9 in. is recommended for the fixing of large size bolts. To facilitate caulking, and to enable this operation to be carried out more effectively, the lead cylinder of the larger size Bolt Anchors is furnished in two sections.

It is recommended in such cases where an exceedingly strong fixing is required that two Rawlplug Bolt Anchors should be used instead of one, being careful to thoroughly caulk the first before placing the second in position and caulking that also.

Quite apart from the immense strain which a Rawlplug Bolt Anchor fixing will withstand, it offers the very great advantage of enabling a fixing by bolt to be completed within a few minutes of the jumping of the hole, and of being able to bear a load immediately after fixing, although it is advisable that the space left round the bolt should be filled in with Portland cement, in order to minimise side strains and to consolidate the material.

It should be clearly understood that the Rawlplug Bolt Anchor does not in any way supersede the well-known Rawlplug, which possesses all its original advantages for fixing fittings by means of wormed screws, whereas the Bolt Anchor enables ordinary bolts to be fixed to any hard material absolutely securely and with the minimum amount of time, thus enabling fitments to be immediately bolted up under great stress.