Schramm 500 Series Guide

HAMMER MAINTENANCE
Service Kit (O-Ring Kit)
•All new SH&B RC hammers are ready to operate upon delivery
•It is recommended to have a rubber service kit on hand whenever dismantling hammers.
•Deterioration of rubber parts will occur if the hammer is overheated. This may be due to
poor lubrication or when the hammer has been bogged. If this occurs, the hammer
should be stripped down for inspection. If the rubber components show any
deterioration they should be replaced. Under normal working conditions the rubber
components of a hammer should last 4000 m. It is recommended to service all
hammers after 4000 m. All internal parts should be checked and all rubber parts
replaced.
Certain operating conditions will require more frequent servicing:
•Operating above 500 psi
•Extremely hard ground conditions
•Corrosive ground water conditions
Hammer Dissemble
500 Series
If possible, break the thread joints on the Drill Rig, otherwise use a hydraulic breakout bench.
Disassemble the hammer with the hammer lying horizontal if possible
1. Remove the Circlip that holds the Adaptor Nozzle.
2. Remove the Adaptor Nozzle and the Inner Tube Together.
3. Remove the Drive Sub, Percussion Bit and Bit Retainer Rings.
4. Push the Piston Bearing Bush up the hammer to clear the Piston Retainer Ring.
5. Remove the Piston Retaining Ring. A small tool with a pointed end can be used to pry
the retaining ring from the groove. Slide the tool into the relief groove and flick the
retainer ring into the piston case. Care should be taken not to scratch the piston Case.
6. Slide the Piston Bearing Bush out of the hammer.
7. Slide the Piston out of the bottom end of the hammer.
8. Unscrew the Top Cylinder from the Piston case.
9. By turning the Top Cylinder upside down the Check Valve and spring should fall out.

Wash all of the components with a cleaning solvent and immediately dry with high pressure air.
Immediately coat all components with lubricant to prevent oxidization as surface damage may
have occurred during drilling allowing oxidization to occur quickly.
600 Series
If possible:
•Breakout all thread joints using the breakout equipment on the drill rig, or
alternatively use a hydraulic breakout bench
•Disassemble the Hammer with the Hammer lying in a horizontal position
•Unscrew the top adaptor & or dig out sub from the top cylinder
•Remove the Circlip from within the top cylinder that retains the Adaptor nozzle
•Remove the Adaptor Nozzle and the Inner Tube Together.
•Remove the Check Valve and Spring
•Unscrew the Top Cylinder from the Piston Case
•Slide the Piston out of the cylinder
•Unscrew Drive Sub/Bit assembly and Bit Retaining Rings from the Piston Case
•To remove the drive sub bush, face the piston case with the drive sub end down and
force onto a block of wood. This should dislodge the bush and you now should be able
to pull it out by hand.
•Wash all of the components with a cleaning solvent and immediately dry with high
pressure air. Immediately coat all components with lubricant to prevent oxidization as
surface damage may have occurred during drilling allowing oxidization to occur quickly.
Note:
•Hammers or parts that have not been adequately sealed and relubricated will deteriorate
quickly due to corrosive damage. Lack of basic protection from moisture, dust or air can
quite often cause damage to hammer components in a short period of time.
•Do not use breakout tools over the threaded area of the piston case, as this may initiate
cracking and will compress the threads making them impossible to loosen.
•Do not use a steel hammer against the cylinder as this will also initiate cracks.
•Do not use drifts or foreign objects inside of the cylinder as it may damage the internal
ground surfaces resulting in premature failure of the hammer
Hammer Reassemble
500 Series
•To ensure optimum performance of your Reverse Circulation DTH Hammer it is
essential to service the hammer regularly.

•Routinely replacing ’O’Rings, check valve seals and springs and bearing bush seals is
good practice and will ensure your hammer does not lose air unnecessarily.
•When re-assembling your hammer ensure all of the components are coated with Rock
Drill Oil. Take particular care to adequately lubricate the internal diameter of the piston
case and the piston.
•For safety and ease of installation the piston case should be horizontal when installing
the piston. Once the Piston, piston retainer ring bearing bush and drive sub are correctly
installed the hammer can be stood vertically for the installation of the remaining
components.
Piston Case
Ensure the internal diameter of the piston case is kept well lubricated. Remove any pick up
marks or burrs with light hand sanding. These imperfections mainly occur due to the introduction
of foreign material during the drilling process.
The piston case is heat treated and as such never apply heat as this may cause cracking or
distortion. When tightening the piston case do not put the chain wrench over the threaded area
as this may cause distortion or cracking.
Piston
Install the piston into the hammer with the smaller diameter facing the drive sub end of the
piston case. Before installation lubricate the piston internally and externally with Rock Drill Oil.
Once installed ensure the piston slides freely in the bore of the piston case.
Bearing Bush
Prior to installation locate the ‘O’Rings onto the bearing bush ensuring that rock drill oil is
adequately coated externally and internally.
Install the bearing bush with the larger diameter facing the drive sub end of the piston case.
Push the bearing bush up to the piston retainer ring.

Please note the bearing bush can only be installed in one direction for the hammer to operate.
The Top Cylinder must be towards the Top Cylinder.
Piston Retainer Ring
Slide the piston past the retainer groove and install the piston retainer Ring. It is easiest to insert
the retainer ring with the split facing towards the bottom of the piston case. A thin steel rod with
a 90° hook at one end will assist in the locating of the retainer into the groove
Bit Retainer Rings
If the hammer is to be stored locate the ‘O’Ring onto the 2 piece Bit retainer rings and slide
them into the piston case until bedded up against the bottom of the bearing bush. If the hammer
is going into service then slide the drive sub onto the Percussion bit with the bit retainer rings
fitted on top of the drive sub. (See Figure 4)
Drive Sub
Coat the Drive Sub threads with no-gall tool joint lubricant, zinc based or equivalent. If hammer
is going into service then install drive sub with percussion bit. If the hammer is to be stored, seal
the drive sub on the bottom end and thread into piston case.
Assembled Reverse Circulation Percussion Bit with Bit Retainer Rings and Drive Sub.
1. Percussion Bit
2. Bit Retainer Rings
3. Drive Sub

Top Sub
Coat the Top sub threads with no-gall tool joint lubricant, zinc based or equivalent. Avoid excess
grease as this can be introduced into the hammer and block airways or internal air ports.
Prior to installation lightly coat the internal diameter and ported section of the Top Cylinder with
Rock Drill Oil.
Slowly slide the Top cylinder into the piston case being careful not to damage the piston or
piston case during installation. Hand Tighten the thread.
Check Valve
Lubricate the check valve and the spring with rock drill oil. Ensure the Check Valve seal is
installed on the internal diameter of the check valve. Drop the check valve spring into the Top
cylinder ensuring it is sitting squarely. Drop the Check valve down onto the spring ensuring it
also sits squarely.
Adapter Nozzle
Apply a light coating of Rock drill oil to the Adaptor Nozzle.
Add the ‘O’ Ring to the external diameter of the adaptor Nozzle. Push the adaptor nozzle down
onto the check valve pushing the check valve down. Continue to push until the Circlip groove in
the Top cylinder is exposed. While holding down the adaptor nozzle install the circlip with circlip
pliers.

Order of Assembly of Check Valve Assembly.
1. Check Valve Spring
2. Check Valve
3. Check Valve Seal (Install into check valve first)
4. Adaptor Nozzle
5. Adaptor Nozzle ‘O’Ring (Installed prior to Assembly)
6. Air Screen
7. Circlip
Inner Tube
Apply a light coating of Rock Drill oil to the entire length of the external diameter of the inner
tube. The internal diameter does not require any lubrication. Install the ’O’Rings on the Inner
Tube. Push the Inner tube down into the Hammer through the Adaptor nozzle. Continue to push
the inner tube until the inner tube sits flush with the adaptor Nozzle.
During Drilling the Inner tube should be checked regularly for wear to prevent internal
contamination of the hammer with Rock Sample. The wear indicator is the shortest length the
inner tube should wear to.
600 Series
It is good practice to replace all ‘O’ Rings and check valve seal during each maintenance
routine.
Ensure all internal parts are coated with rock drill oil. Take particular care to liberally coat the
internal bores of the piston and piston case.
For safety and ease of installation, assembly of the piston into the cylinder is best carried out
with the cylinder in the horizontal position. Once the piston, piston retaining ring, drive sub bush,
bit ring and drive sub is installed, the hammer should be stood vertical for installation of the
remaining components from the top end.
•Lubricate the internal bore of the cylinder with rock drill oil.
•Where applicable, insert the piston retainer ring into the cylinder from the bottom end, if
not already in place

•Insert the lubricated drive sub bush until it stops on the piston retainer ring/shoulder.
•Insert the bit retainer ring until it rests on the drive sub bush.
•Coat the thread on the drive sub with no-gall tool joint lubricant and screw into the
cylinder with the shroud placed over the top.
•Note that there will be a gap between the drive sub and cylinder unless there is a shroud
assembled to the drive sub.
•Lubricate all the piston’s surfaces (external & internal) with rock drill oil.
•Stand the cylinder on a slight incline and carefully lower the piston into the cylinder from
the top end until it rests on the drive sub bush.
•Coat the top cylinder thread with a tool joint grease and lubricate all other surfaces.
•Screw the top cylinder into the cylinder.
•Insert the check valve spring, check valve and adaptor nozzle/distributor into the top sub
and then lock in place with the circlip.
Piston Case
Ensure the internal diameter of the piston case is kept well lubricated. Remove any pick up
marks or burrs with light hand sanding. These imperfections mainly occur due to the
introduction of foreign material during the drilling process.
The piston case is heat treated and as such never apply heat as this may cause cracking or
distortion. When tightening the piston case do not put the chain wrench over the threaded area
as this may cause distortion or cracking
Piston Bush
Prior to installation locate the O-Ring's onto the Piston bush ensuring that rock drill oil is
adequately coated externally and internally.
Install the bearing bush with the larger internal diameter facing the drive sub end of the piston
case. Locate the bearing bush up to the piston retainer ring, O-Ring end first.
To secure the Piston bush in place force the Piston case (top cylinder end first) onto a block of
wood and hear it drop into position.

Please note the bearing bush must only be installed in one direction for the hammer to operate.
Bit Retainer Rings
If the hammer is to be stored fit the Bit retainer rings into the piston case until resting up against
the bottom of the bearing bush. If the hammer is going into service then fit the drive sub onto the
Percussion bit with the bit retainer rings fitted on top of the drive sub.
Drive Sub
Coat the Drive Sub threads with no-gall tool joint lubricant, zinc based or equivalent. If hammer
is going into service then install drive sub with percussion bit. If the hammer is to be stored, seal
the drive sub on the bottom end and thread into piston case.
Assembled Reverse Circulation Bit with Bit Retainer Rings and Drive Sub.
1. Percussion Bit

2. Bit Retainer Rings
3. Drive Sub
Piston
Install the piston into the hammer with the smaller diameter facing the drive sub end of the
piston case. Before installation lubricate the piston internally and externally with Rock Drill Oil.
Once installed ensure the piston slides freely in the bore of the piston case.
Top Cylinder
Coat the Top cylinder threads with no-gall tool joint lubricant, zinc based or equivalent. Avoid
excess grease as this can be introduced into the hammer and block airways or internal air
ports..
Prior to installation lightly coat the internal diameter and ported section of the Top Cylinder with
Rock Drill Oil.
Slowly slide the Top cylinder into the piston case being careful not to damage the piston or
piston case during installation. Hand Tighten the thread.

Check Valve
Lubricate the check valve and the spring with rock drill oil. Ensure the Check Valve seal is
installed on the internal diameter of the check valve. Drop the check valve spring into the Top
cylinder ensuring it is sitting squarely. Place the Check valve down onto the spring ensuring it
also sits squarely.
Adaptor Nozzle
Apply a light coating of Rock drill oil to the Adaptor Nozzle. Add the ‘O’ Ring to the external
diameter of the adaptor Nozzle. Install the airscreen over the adaptor nozzle then continue to
push the adaptor nozzle down onto the check valve pushing the check valve down. Continue to
push until the Circlip groove in the Top cylinder is exposed. While holding down the adaptor
nozzle install the circlip with circlip pliers.
Order of Assembly of Check Valve Assembly
1. Check Valve Spring
2. Check Valve
3. Check Valve Seal (Install into check valve first)
4. Adaptor Nozzle
5. Adaptor Nozzle ‘O’Ring (Installed prior to Assembly)
6. Air Screen
7. Circlip

Inner tube
Apply a light coating of Rock Drill oil to the entire length of the external diameter of the inner
tube. The internal diameter does not require any lubrication. Install the ’O’Rings on the Inner
Tube. Push the Inner tube down into the Hammer through the Adaptor nozzle. Continue to push
the inner tube until the inner tube sits flush with the adaptor Nozzle.
During Drilling the Inner tube should be checked regularly for wear to prevent internal
contamination of the hammer with Rock Sample. The wear indicator is the shortest length the
inner tube should wear to.
Hammer Storage
Short term Storage (1 or 2 weeks)
1. Blow the hammer clear of all water while still on the Drill Rig
2. Pour 1 litre of Rock Drill Oil into the Hammer
3. Turn the Air on and cycle the hammer against a block of wood for 10 seconds. This will
lubricate the internal components.
4. Remove the hammer from the Drill Rig and cap the Top Sub end of the Hammer

Long term Storage (more than 3 weeks)
Completely dismantle the hammer and follow the hammer reassembly direction of this manual.
Store the hammer with both ends capped in a dry place, with the hammer in a horizontal
position.
Before re-starting after long periods of inactivity, disassemble the hammer and inspect all
internal components for rust. Use a light emery to remove any oxidization , completely wash and
dry the hammer and re-assemble following the directions in this manual.
Recommendations
Hammers and bits that are used in drilling wet holes or have water or foam injected should be
stripped, inspected for corrosion then suitably service every 60 –80 hours of operation. In
particular, both male and female threads should be liberally coated with grease to provide a
barrier against corrosion attack, especially non-contact surfaces where water can accumulate.
SH&B recommend the use of molybdenum-disulphide additive to hammer oil, primarily to
minimise ‘heat checking’ on pistons. Molybdenum-disulphide’s affinity (attraction) to steel
provides excellent protection against corrosion to both the cylinder bore and piston.
Hammers SHOULD NEVER be left, between shifts, PARKED in the hole under water. A 12 hour
exposure of a steel surface to an ‘electrolyte’ is sufficient time to establish significant corrosion
pitting.
The correct procedure is to pull the hammer back above the water level, blow dry with air, and
pour a quantity of oil down the drill pipe then blow air through the hammer to hopefully cover its
components with a protective film of oil. Some drilling personnel may argue that “pull back”
costs time and money. This consideration must be weighed up against the cost of a
replacement piston (usually $2-3K) and possible consequential damage and replacement of the
cylinder and as well the down time when failure occurs.
Storage of a hammer for any period of time requires that it be stripped to its component pieces,
thoroughly cleaned and dried and the internal pieces liberally coated with oil and the cylinder
thread joints liberally covered with grease.