Rewinding Memories: A Look Back at Our Partnership with Severstal

Sometimes, you stumble upon old files and find pieces of the past staring back at you. Today, I reopened a project report from years ago and was instantly pulled into the memory of our collaboration with Severstal—a steel giant that no longer exists today.

The world of steel has always been intense, but nothing prepared me for how quickly landscapes can change. Back then, Severstal was an influential player, and we were proud to work alongside them. Now, the group is gone—dissolved, acquired, or simply faded amid the relentless competition that defines our industry.

It’s a tough reminder of how fragile global supply chains can be, especially as trade tensions between the U.S. and China continue to ripple across the steel sector. Tariffs, anti-dumping probes, and localization policies have redrawn the map of international steel trade. In this climate, partnerships like the one we had with Severstal feel both nostalgic and symbolic—of a time when collaboration across borders was somewhat easier, and certainly more hopeful.

Below is the post I wrote in 2013, after our team’s visit to Severstal’s plant in Russia. Reading it now feels bittersweet—like watching a scene from a movie you once loved, knowing there won’t be a sequel.

December 2013 — Visiting Severstal

After getting approval from Severstal, our team visited their steel plant on December 19, 2013. The facility was far more expansive than I had imagined. As we walked through the complex, one slogan kept catching our eyes: “We Make Steel Safely.” That phrase truly captures the core philosophy of Severstal. It shows that for a quality steel producer, safety always comes first.

During our discussions, we expressed interest in touring the workshop. They asked us to wait briefly, and within five minutes, the reason became clear: we needed to put on safety helmets—standard procedure there. While walking through the production area, we spotted a slag pot we had manufactured back in 2010, still in active service after all these years. It was like a reunion with an old friend. That unit weighs 44 tons and represents immense effort from our side. The entire process—from initial wooden pattern making, molding, and casting, to heat treatment and final cleaning—was carried out with the same care one would give to raising a child. We always worry about whether every detail is perfect. Seeing it there, still operating reliably, filled me with pride. Best wishes to my dear slag pot—model C501. May you continue to serve well!

Witness the shipment of a custom-built 44-ton slag pot, engineered for endurance and performance. This marks the completion of another successful project for our client.

The Slag Pot That Remained: Memories of Severstal

The CEO of world number two miner Rio Tinto last week told an investor conference the quality of Chinese mining equipment is catching up to that of the major US manufacturers.

The Wall Street Journal quotes Rio Tinto (LON:RIO) CEO Sam Walsh as saying that the Anglo-Australian giant has been increasing purchases of heavy equipment and other items from India and China, and has found the quality impressive.

Among RIO’s purchases were heavy-duty trucks, equipment for loading ships and rail cars that carry ore.

Without naming any names, Walsh said “funnily enough” on the rail cars “the quality actually was much higher” compared to the miner’s traditional supplier: “Instead of spot welds, for example, on the sheet metal they were actually continuous welds.”

A JP Morgan analyst said that quality at Chinese equipment makers can vary widely, but “it’s incredible the speed at which they are coming up the quality curve.”

It’s a development that spells tougher competition down the line for a host of mining equipment suppliers, including the likes of Caterpillar (NYSE:CAT), Joy Global (NYSE:JOY), Komatsu and Liebherr.

Leaders CAT and Joy Global are having a tough year. In October, world number one supplier Caterpillar lowered guidance and reported revenue numbers below analysts expectations, while Joy Global last week reported a 26% slump in sales as the slowdown in mining capital expenditure continues.

Other manufacturers like Belarusian mining equipment manufacturer Belaz are also muscling in on the traditional leaders turf. Belaz is testing a truck which will be the world’s largest capable of carrying a 450 tonnes payload.

 From http://www.mining.com/rio-tinto-says-chinese-now-make-much-higher-quality-mining-equipment-83928/?utm_source=digest-en-mining-131216&utm_medium=email&utm_campaign=digest

product coverage of the mining, metallurgy, locomotives, ships, machine tools, military and other industries worldwide ,Product precision level reached AGMA 12-13 (IT4-5).
Processing range:

1. spiral bevel gear milling, scraping hardened tooth: The largest diameter Φ2000mm, maximum modulus 45mm;
2. spiral bevel gear grinding teeth: The largest diameter Φ960mm, maximum modulus 22mm;
3. spiral bevel gear shaft Ferry Maximum: Φ400mm;

They are also used in High-speed Wire Rolling Mill, Rolling Mill, Marine, Cement Mil, Large Mining Dump-truck,
Spiral Bevel Gear of Hard face
Grinding Spiral Bevel Gear of Hard Face
Shaving Spiral Bevel Gear of Hard Face

Isparta – Göltas Cimento A.S. is operating two clinker production lines in Isparta, about 130 km North of Antalya, Turkey. As part of the existing lines, Göltas Cimento already successfully operates two Loesche Vertical Roller Mills; one for cement raw material grinding and the other one for coal grinding.
In order to increase the cement grinding capacity on site, Göltas Cimento and Loesche signed a contract in July 2013, for the supply of a third Loesche Vertical Roller Mill. The chosen Loesche Vertical Roller Mill – Type LM 56.3+3 – will be producing at least three different cement types, from a standard OPC cement to various types of composite cements. Production rates of up to 230 tph are foreseen.
Göltas Cimento realized that the Loesche Vertical Roller Mill technology is superior over all other available grinding systems. Loesche’s innovative Compact Plant Design for cement grinding plants was a major reason for Göltas Cimento to choose a Loesche Vertical Roller Mill for its project. This concept ensured that the grinding plant can be built into the very limited available plant footprint.
The new Loesche Compact Plant Design eliminates the necessity for a large and expensive mill building, leading to massive savings in required plant plot, in cost for structural steelworks and civil works as well as in erection time. The advanced Loesche technology, ensuring the production of various excellent product qualities, with high availability and very low energy consumption of the complete grinding plant, were further decision factors for Göltas Cimento to trust Loesche for the new cement mill.
This is, amongst other Loesche innovations in this direction, possible due to Loesche’s newly developed LDC classifier. This classifier is equipped
with a patented gas flow straightener called “VORTEX Rectifier” which ensures an already homogeneous airstream at the classifier exit. Due to
that a horizontal mill exit directly into the mill filter is possible. This leads for example into a reduced pressure drop of the mill system hence into
savings in the specific power consumption of the complete grinding system.

The cement plant of Göltas Cimento A.S. in Isparta, Turkey

The material is extracted from http://www.loesche.com/en/data-2/news/latest-news/goeltas-cimento-s-first-vertical-roller-mill-for-cement-grinding-will-be-supplied-by-loesche/

how to machine it. Let’s take the large gear used in coal grinding Φ3.8×7.25+3.5m for instance and make a analysis to its machining procedure.

二、The large gear structure and process datum
The large gear used for grinding machine with the size of Φ3.8×7.25+3.5m, material ZG310-570, precision level 9-9-8-JM（GB10095-88）,technical data: Z=206，m=28,α=20°, Tooth depth coefficients h*=1, modification coefficient x=2.8, addendum circle diameter: da=5963.76mm。For dimension and tolerance, see DWG 1

Process datum: According to tolerance and assembling of large gear, its datum diameter should beΦ 4345(female end), The position of reference surface B,C,A will affect position accuracy of hole 48-Φ52, which lead to affect installation precision of large gear, if so, the cylinder of grinding machine cannot work pretty well.
三、The machining procedure：
The large gear is kind of big cast steel with enough margin. Because of two halves that assemble as one, the every half of the cast steel is easily deformed. IN order to ensure the machining margin, the scrape is necessary. The scrape can keep a good connection between the two halves, and it can also check whether the margin is enough or not. According to the existing scrape on the end face, keep the two halves of cast steel in the right position during assembling them as one. And then boring connention holes and pin holes , fasten the two halves with bolts. Machining inner and outer circle as well as various end faces by vertical lathe. The lathing here is one of the most important procedure. To ensure all the dimensions and tolerances and keep the product undeformed in the couse of lathing as per drawing, machine it as follows:
1 .Keep the more flat end face of the blank as datum, put it on the trim plate , and make it on the right position according to the existing scrape on the surface of the product, then clamp it tightly(See DWG 2). Rough-lathe all the parts of the

product as much as possible, keep margin for 5mm, then reverse end for end , Rough-lathe the rest of the product, keep margin for 5mm.
2 Remove the product from the lathe, put it on the platform, loosen the bolts, and make it deformed for 24 hours in a natural way (or vibration failure for over 2 hours). That is to release the inner stress caused after rough machining.
3．Re-fasten the bolts and pins firmly.
4．Place the product flatwise on the trim plates with same high, clamp inner circle of Φ5700 (See DWG 3)

Make the product on the right position in accordance of machined surfaces, and the clamp force does not have to be too strong lest it would be deformed.
5 Fine-lathe various parts of the product as per drawing, scrape pitch circle with the tip of lathe tool, then machine female end of Φ4345. The inner hole and end face can be seen as reference for assembling.
6 Reverse ends for end, clamp as showed on the DWG 3, fine lathe the rest of product as per requirement showed on the drawing.
After lathing, the tooth can be machined. To ensure the accuracy of the tooth, decrease the load of the lathe and prolong the life service of the lathe, the product can be machined by two different machines.
1． First, scrape the outline of the tooth, the scrape should be on the non-reference surface, then clamp the product on the gear milling machine, rough milling the tooth with fonger-shaped milling tool. Keep margin 2-3mm for each side, and keep the margin even.
2．After rough tooth milling, clamp the product on the Φ8m gear hobbling machine, and then fine-hobbling the tooth in two runs till it meets the requirement of the drawing.
After the tooth is completed, scrape and drill holes and thread holes, but the holes of 4-Φ50H7 should be drilled upon assembly with flange holes on the cylinder. Therefore drill the holes to 8-Φ42 first , then assemble cylinder together, drill them at once in accordance with drawing.
Last, take the large gear apart in two, fasten them with tightening device, that will be convenient for transportation.
四、Conclusions：
It is imperative to prepare a machining procedure according to the reference surface when setting a rule of machining for large cast steels, especially for the large gears used in grinding machines. Meanwhile, the deformation should be taken into consideration during machining.
It is, therefore, necessary to increase the frequency of the product clamping. If the margin is too much, the rough-milling should be carried out before fine-milling. That can decrease the load of the milling Chan chine; increase the life service of the machine.

CMI find us from net, they want to visit our company. so on Oct 18, MHMHD show CMI around our plant and related shop.

CMI visited foundry who cooperate us for many years, its quality is best and his workers have good skills.

this is the time that

we are discussing their products.

from MHMHD.

]]> https://mhmhd.com/a-sudden-inquiry-from-franch/feed/ 0 https://mhmhd.com/bull-gear/ https://mhmhd.com/bull-gear/#respond Thu, 26 Sep 2013 03:32:43 +0000 http://mhmhd.com/?p=745 Continue reading →]]>

Luoyang /Mar 26,2013    Canada client need bull gear

Gerry, our old friend, he need bull gear for dia 4*6m ball mill  , he has been visited our company three times, this time he hope we cooperate again.

he tell us, his pinion shaft for φ4×6m BALL MILL  always break ,break ALL SHAFT edges,  service life  is no more than 3 months.  he has no good idea, through discussion with our engineer, he is very satisfy our company. he praise our company is high technocal company.

Xia zhao/September 2, 2013

(July 2) , Poland client visit mhmhd .  this is  successful visiting, they satisfy our plant very much,  our experienced team of the quality department ensures inlet inspections, process inspections and final inspections of all products according to customer’s requirements. The quality system is certified as per ISO 9001. our  company ensures a wide range of quality inspections from quality plans, dimension checks, all non-destructive tests.  finally in reciprocal banquet, Poland  client said,”our friendship is like Peony in full  bloom.

MHMHD finish slag pot on 40ton/piece , this is photo for President Zhang is on the way  to measuring .