{"id":66635,"date":"2026-08-15T08:00:42","date_gmt":"2026-08-14T23:00:42","guid":{"rendered":"https:\/\/norimen.net\/?p=66635"},"modified":"2026-08-14T00:09:07","modified_gmt":"2026-08-13T15:09:07","slug":"rotary-percussion-consumables","status":"publish","type":"post","link":"https:\/\/norimen.net\/en\/rotary-percussion-consumables\/","title":{"rendered":"Rotary Percussion Consumables | Explaining the Service Life, Life Extension, and Repair of Cleaning Adapters and Cam Followers Using Real-World Examples"},"content":{"rendered":"

Hello, everyone.<\/p>\n

This is Enta.<\/p>\n

Obon is coming to an end, but I'm just going about my usual business, dealing with all sorts of paperwork lol<\/p>\n

The scorching sun this time of year really takes a toll on your body, but the machines are wearing out just as fast, lol.<\/p>\n

But that's beside the point.<\/p>\n

In this post, I\u2019ll discuss consumable parts for rotary percussion instruments in the following order: \u201cWhich parts wear out?\u201d, \u201cWhy do they wear out?\u201d, \u201cHow much do they cost?\u201d, and \u201cHow can you extend their lifespan?\u201d<\/p>\n

If you work in the anchoring business or drill holes in slopes, you should be familiar with all of these parts.<\/p>\n

To put it another way, it\u2019s a part we\u2019re so used to seeing that we simply replace it when it breaks.<\/p>\n

Rotary percussion instruments are full of wear-and-tear parts.<\/h2>\n

A rotary percussion drill, as the name suggests, is a machine that drills holes by \u201crotating\u201d and \u201cstriking.\u201d
\nCompared to rotary-only systems, its biggest advantage is that it can advance quickly even through hard bedrock.<\/p>\n

However, all of that impact is reflected right back onto the machine itself.
\nA drifter, shank rod, coupling, rod, bit, casing, swivel, and a cam follower that supports the hammer.
\nNo matter where you look, every part seems to be a \"consumable.\"<\/p>\n

To be honest, this is the main reason why people say Anchor-ya\u2019s construction rates are high.
\nEven when it comes to a single hydraulic hose, some hoses designed for drilling machines can cost more than three times the standard price compared to off-the-shelf products available at your average hydraulic hose shop.
\nIt's ridiculously expensive, isn't it? lol<\/p>\n

\"Skid-Type
Manufactured by Teisaku, 4.5 metric tons<\/figcaption><\/figure>\n

The Roles of the Cleaning Swivel and Cleaning Adapter<\/h2>\n

Among these consumable parts, we\u2019ll start by looking at the ones that are particularly expensive and prone to problems.
\nFirst off, do you know about this?<\/p>\n

\"Cleaning<\/p>\n

This is a part called a cleaning adapter.<\/p>\n

\"Complete<\/p>\n

This yellow exterior is the entire Cleaning Swivel unit, and the cleaning adapter I mentioned earlier fits inside it.<\/p>\n

Put simply, a cleaning swivel is a component designed to \u201cfeed water or air from a stationary pipe into a rotating rod and discharge the resulting slime to the outside.\u201d
\nWater is fed from the feed pump through the suction port and via the cleaning adapter into the inner rod, and the water exiting from the bit at the tip pushes the slime upward through the gap between the inner diameter of the casing and the outer diameter of the inner rod.
\nIn other words, the exit points for expelling that slime are the several large holes located next to the cleaning adapter.
\n(The names of parts may vary by manufacturer. Since various companies, such as Koken Kogyo with its \u201cArrow Cleaning Swivel,\u201d offer similar products, please refer to the user manual for your specific machine and the manufacturer\u2019s documentation for details.)<\/p>\n

The problem here is the slime that gets released.
\nSince both small and large particles are mixed together and pass through while scraping against the sealing surface, friction occurs between the seal and the slime.
\nAnd that\u2019s what\u2019s actually being used to grind away this incredibly hard chunk of iron.<\/p>\n

If it is worn down, the contact surface will become rough, and the gasket will no longer function properly.
\nIf that happens, it will leak from the cleaning swivel.
\nA small leak isn't a big deal, but eventually, the cleaning swivel itself will break.<\/p>\n

This set\u2014the cleaning adapter and cleaning swivel\u2014cost us about 300,000 yen when we replaced it.<\/p>\n

It's even more expensive now! It's seriously crazy expensive lol<\/p>\n

It's incredibly expensive.
\n\"A<\/p>\n

I think about 1.5 mm has been shaved off the cleaning adapter shown in the photo.
\nAt this point, it needs to be replaced, so it can't be used anymore.<\/p>\n

The cleaning swivel (the yellow outer part shown in the photo above) is equipped with a grease nipple for lubrication.
\nI grease this area about twice a day.
\nEven so, it gets cut.
\nI know it\u2019s a consumable item, so there\u2019s nothing to be done about it, but service providers naturally want to extend its life as much as possible, don\u2019t they?<\/p>\n

\"Conceptual<\/p>\n

Air Drilling Drastically Shorts the Service Life of Cleaning Adapters<\/h2>\n

That said, there is one drilling method that you should avoid as much as possible.<\/p>\n

Air Drilling<\/strong>That's it!<\/p>\n

Drilling with a swivel uses up air like crazy. Things just keep breaking.<\/p>\n

It is said that when double-pipe drilling is performed using air drilling, the service life of the cleaning adapter is 200 hours or less.
\nSince it only lasts 33 days based on 6 hours of operation per day, it\u2019s basically like throwing away about 10,000 yen a day.
\n(This figure of \"less than 200 hours\" is based on actual maintenance records for the equipment, as reported by a mechanic at a leasing company. Please keep in mind that this is not an official figure released by the manufacturer.)<\/p>\n

The logic is simple.
\nWith water drilling, the slime flows out along with the water in a thick, gooey stream, but with air drilling, dry rock dust is blown out at high speed.
\nIt\u2019s essentially the same process as sandblasting, but it\u2019s done inside the parts every day.
\nWell, of course it'll wear down.<\/p>\n

Therefore, we recommend using the water-flush method for double-pipe drilling whenever possible.
\nThere are some job sites where water simply can\u2019t be used, but even just reducing the amount of water and adding air makes a big difference.
\nSince it really helps keep dust down, digging a water trench is definitely the way to go.<\/p>\n

Speaking of dust, the Regulations for the Prevention of Dust-Related Illnesses also stipulate measures to keep the source of dust\u2014such as operations involving percussion rock drills\u2014in a moist state.
\n*I have not personally cross-referenced the text up to the relevant section number. For details, please refer to the full text of the Ministry of Health, Labor and Welfare\u2019s Regulations on the Prevention of Dust-Related Diseases.
\nI think this is a rare and straightforward example of how extending the life of machinery and protecting workers' health go hand in hand.<\/p>\n

Of course, there are geological conditions where using water can destabilize slopes, and it also adds the hassle of drainage treatment.
\nThis depends on the on-site conditions, but the decision will vary depending on whether you factor in the cost of \u201creduced machine usage when excavating with compressed air\u201d from the outset.
\nThe worst part is when you dig a hole without realizing it and then turn pale when you see the 300,000 bill later, lol.<\/p>\n

\"How<\/p>\n

List the main consumables and their recommended replacement intervals<\/h2>\n

Let's take a moment to check the consumables related to the rotary percussion system.
\nSince the cost and lifespan vary significantly depending on the model, soil conditions, and usage, please consider this based on our personal experience and actual results.
\nThis is not the lifespan stated by the manufacturer.<\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n
Body Part<\/th>\nWhat does this part do?<\/th>\nHow It Wears Down and Breaks<\/th>\nOur Company's Guidelines for Replacement (Based on Experience)<\/th>\n<\/tr>\n<\/thead>\n
Cleaning Adapter<\/td>\nSlime outlet. Features a sealing surface.<\/td>\nThe inner surface is eroded by the slime, forming grooves. It may also crack.<\/td>\nI've heard that if you focus on air drilling, it takes less than 200 hours. If you focus on water drilling, it takes considerably longer.<\/td>\n<\/tr>\n
Cleaning Swivel Unit<\/td>\nConnecting the rotating side and the stationary side<\/td>\nIf you ignore a leak in the adapter, it can damage the main unit as well.<\/td>\nAdapters usually need to be replaced about once every two to three adapters.<\/td>\n<\/tr>\n
Shank Rod<\/td>\nTransmits impacts on the inner casing to the rod<\/td>\nWear on the threaded portion, flat spots on the striking face<\/td>\nIf the threaded portion is worn down, replace it with a new one instead of repairing it.<\/td>\n<\/tr>\n
Coupling<\/td>\nConnecting the outer casings<\/td>\nWear, loosening, or seizing of threaded parts<\/td>\nSame as above. Replace immediately if the screw becomes loose.<\/td>\n<\/tr>\n
Rod<\/td>\nTransmitting the impact and rotation to the tip<\/td>\nWear on the outer diameter, bending, and damage to the threaded section<\/td>\nReplace it if the threaded portion is worn down or cracked.<\/td>\n<\/tr>\n
Bit<\/td>\nActually breaking rocks<\/td>\nWear and Breakage of Cemented Carbide Inserts<\/td>\nIt varies greatly depending on the geology. In hard rock, it wears out quickly.<\/td>\n<\/tr>\n
Casing<\/td>\nHole Wall Retention<\/td>\nWear on the circumferential surface, damage to the threaded section<\/td>\nIt depends on the geology and the drilling depth.<\/td>\n<\/tr>\n
Cam follower<\/td>\nSupporting the Hammer (Drifter) on the rails<\/td>\nWear on the outer ring, cracked bearings, defective nipples<\/td>\nReplace them one set at a time before they break.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

As you can see when you line them up like this,If a product has worn-out threads, don't try to repair it\u2014just buy a new one.<\/strong>...that's the basic idea.
\n(It's not that repairs can't be done, but since they'll weaken the item, please assume that they generally aren't possible.)<\/p>\n

If the threaded portion of the shank rod or the coupling is worn out, don't even try to fix it\u2014just buy a new one (lol).
\nAfter all, we can't repair just anything and everything.<\/p>\n

On the other hand, for parts with smooth contact surfaces\u2014such as cleaning adapters\u2014it may be possible to rebuild the surface.
\nIn the next section, I'll share the results of actually sending it in for repair.<\/p>\n

Is Repairing (Surface Restoration) of Consumables Really Effective?<\/h2>\n

I heard some time ago that there\u2019s a technology that can restore this dented surface to its original condition.
\nWhat's more, it's cheaper than buying it, and after processing, it becomes harder than it was before.
\nSo, I decided to give it a try.<\/p>\n

The other day, that cleaning adapter came back from being machined.<\/p>\n

\"Cleaning<\/p>\n

\u2191\u2191\u2191After<\/p>\n

What do you think?<\/p>\n

\"Cleaning<\/p>\n

\u2191\u2191\u2191Before<\/p>\n

It came back without that groove.<\/p>\n

\"Sliding<\/p>\n

\u2191\u2191\u2191After<\/p>\n

It's super smooth.<\/p>\n

\"Cleaning<\/p>\n

\u2191\u2191\u2191After<\/p>\n

You can clearly see where the repairs were made.
\nYou can tell there's a slight difference just by touching it.
\nSince the accuracy is at the 1\/100 level, it should work fine for a gasket.<\/p>\n

\"The<\/p>\n

\u2191\u2191\u2191Before<\/p>\n

It came back looking much better\u2014all those dents are gone\u2014so I'm happy with how it looks.<\/p>\n

One thing to watch out for during repairs is that the \"base material shrinks.\"<\/h3>\n

The issue is strength.<\/p>\n

That's because this repair method involves lightly grinding down the base material first and then rebuilding the surface.
\nRemoving material from the base metal naturally makes that area thinner, which means the overall strength is reduced.<\/p>\n

We were told that the surface treatment itself is stronger than the plating on genuine parts.<\/p>\n

Generally speaking, superhard coatings applied via thermal spraying (particularly HVOF, or high-velocity oxygen fuel spraying) are commonly used for surface treatments designed to provide wear resistance, and<\/p>\n

According to materials provided by a thermal spraying company, while the hardness is comparable to that of hard chrome plating, its wear resistance is several times greater.
\n*This is a general explanation based on technical documentation from thermal spray contractors and does not specify the exact process used for the parts we supplied in this instance. When placing an order, please confirm the processing details and coating type with the contractor.<\/p>\n

However, no matter how hard the surface becomes, it\u2019s ultimately useless if the base material breaks.
\nSince this involves both shaving and building up the material, I think the limit is probably around two repair sessions.<\/p>\n

Since cleaning adapters usually break at the hole, it\u2019s unlikely that the repaired, smooth surface would break, though...<\/p>\n

You won't know until you try it, so it'll be a bit of an experiment for a while.<\/p>\n

That said, the repair costs aren't exactly cheap.
\nSince it\u2019s not exactly dramatically cheaper than the 400,000 yen price tag for a brand-new one, to be honest, there are some aspects where it\u2019s better to just buy a brand-new one.<\/p>\n

There is one more risk I\u2019d like you to keep in mind.
\nIt\u2019s quite a hassle when a cleaning adapter breaks inside a hole or inside the machine.<\/strong>
\nSince it\u2019s extremely difficult to remove, pushing it to the very limit of its lifespan isn\u2019t necessarily the best approach.
\nIt\u2019s no good if you think you\u2019re saving money by extending the equipment\u2019s life, only to end up shutting down operations for a day to handle the cleanup.<\/p>\n

\"Comparison<\/p>\n

Cam followers are standard wear parts for rotary percussion hammers.<\/h2>\n

This is a part that anchor shop workers are used to seeing, but if it breaks, it can cause serious problems.<\/p>\n

\"Cam<\/p>\n

I imagine there are some people who have never heard of it.
\nThis is called a cam follower.
\nThis is a bearing that supports the hammer (drifter) of the rotary percussion mechanism and runs along the rail.<\/p>\n

\"Bearings<\/p>\n

As shown in the photo above, they are attached to the front, back, left, and right corners.
\nEven when it sways from side to side, it doesn't wobble more than necessary, thereby minimizing mechanical friction.<\/p>\n

As a component, the cam follower is a so-called stud-type track roller\u2014a common mechanical component for which NTN and NSK publish catalogs.<\/p>\n

The cam follower on a drilling machine is subjected to impact loads day in and day out.
\n\"Greasing regularly\" is an absolutely essential part of my daily routine!<\/p>\n

\"An<\/p>\n

As it gets older, the grease nipple wears out, and the bearing inside starts to crack.
\nThe cam follower in the photo isn't cracked, but in some cases, it can crack completely.
\nThat\u2019s how much force is being applied.<\/p>\n

Replace the cam follower as a complete set.<\/h3>\n

It\u2019s such an important part, but it\u2019s actually pretty expensive, lol.<\/p>\n

There are four installation locations, and three are used at each location. That\u2019s why we need a total of 12.
\nIf you replace the parts one by one starting with the broken ones, it should be fine for the most part, but if you're going to replace them, it's less likely to break if you replace them as a set.<\/p>\n

The reason is simple: if you replace just one part with a new one, the load will be concentrated on that single part.
\nTwo old ones with reduced outer diameters and one new one with an increased outer diameter.
\nIt goes without saying which one will hit the rail, doesn't it?<\/p>\n

Roughly speaking, when we bought them, they were around 4,500 yen each.
\nIf you replace all 12, it will cost in the 50,000 yen range. If you replace 3 in one location, it will cost about 14,000 yen.
\nIt's even more expensive now! The price keeps going up and up\u2014I can't take it anymore...<\/p>\n

There are some inexpensive Korean-made products, but they aren't very durable (compared to our products).
\nAs for domestic manufacturers, would it be NTN or NSK?
\nI'm not really a fan of the press-fit grease nipple, though... lol<\/p>\n

\"Grease<\/p>\n

Press-fit nipples have the trifecta of problems: they come loose easily, are hard to insert, and are difficult to grease with a grease gun.
\nHowever, if you skip greasing it at this point, the internal rollers could crack, and the broken pieces could damage the rail, leading to the worst-case scenario of having to repair the entire rail.
\nEven though I complain about the shape of the nipple, I have no choice but to fill it up every day, lol.<\/p>\n

Tips for Extending the Life of Consumables That You Can Start Using Tomorrow<\/h2>\n

Finally, I\u2019ll list the inspections we actually perform (and often skip\u2014only to learn the hard way).<\/p>\n

    \n
  • Grease the grease nipple on the cleaning swivel about twice a day.<\/li>\n
  • Greasing the 12 cam followers and checking the contact surfaces and play on the outer circumference<\/li>\n
  • Check the amount of drilling fluid and the color of the return fluid every day. If the return fluid starts to dry out, check the fluid level.<\/li>\n
  • If you notice a leak from the swivel, don't assume it's \"still usable\"; treat it as a sign that it's time to replace the seals and gaskets.<\/li>\n
  • Apply rod grease to the threaded portion of the rod coupling every time. If the thread becomes loose, replace it with a new one without hesitation.<\/li>\n
  • As a general rule, double-pipe drilling is performed using water. On days when the use of compressed air is unavoidable, the resulting additional consumption must be factored into the schedule and cost estimates.<\/li>\n<\/ul>\n

    There isn't a single flashy thing about it.
    \nBut what happens when you factor in the difference over the course of a year between a part that wears out after 200 hours\u2014costing 400,000\u2014and a part that lasts twice as long with regular greasing?
    \nThat's exactly where the anchor shop makes its profit.<\/p>\n

    I know I sound like I'm talking down to everyone here, but when things get busy, I completely forget to do inspections.<\/p>\n

    Actually, there are times when I can't get my paperwork or invoices done on time, lol.<\/p>\n

    Even so, since the amount we spend on consumables directly translates to cash outflow, this is one area where I want to be really thorough!<\/p>\n

    The reason people say Anchor-ya's construction rates are high is that these consumables are outrageously expensive.<\/p>\n

    The same goes for the casing\u2014everything, from start to finish, is just so expensive.<\/p>\n

    But since we can\u2019t do our jobs without these supplies, we should make sure to do a thorough job on the high-paying projects, right? lol<\/p>\n

    And unfortunately, with inflation causing parts prices to keep rising, things are likely to get even worse...<\/p>\n

    Prices and unit costs are out of balance.<\/p>\n

     <\/p>\n

    See you later.<\/p>\n

    Greasing Is the Basis of Maintenance | Measures to Prevent Fatal Accidents at NEXCO Construction Sites<\/a><\/p><\/blockquote>\n