parallel plate and gauge blocks

metalwork equipment - hobbiest collection

parallel plate stet 140mm

parallel-plate 140mm Parallel Unterlagen 140mm verschiedene Breiten und Dicken Stahl
The top cover is made of tigerwood and a needle tree. Surface polished with blond shellac. all wood parts are milled on the CNC machine parallel plates with a length  of 140mm it is a please on the table
Parallel plates are very useful, allowing a parallel position of the workpiece in the vice. The shown set made from a quality manufacturer. Parallel plates are must have for working with a milling machine.

Ceramic Cera Block Set

Cera Block Set Label Keramik Endmaße Endmaße
Mitutoyo Cera Block Set Grade 0 such a Cera Block Set is something for life different size up to 60mm material is almost ageing free, the biggest advantage. In addition this ceramic is very hard and need no Vaseline.
Polished high quality ceramic and accurate with Grade 0.
verschiedene Größen Keramik Endmaß 60mm cera gauge
a pleasure to work with them the largest one they are very hard, be careful, they can break

Tungsten Gauge Block Set

Tungsten Gauge Block Set Hommel Hercules Handgloves Tungsten Carbide
Tungsten Gauge Block Set in a shellac polished wooden box Hommel Hercules I put inside a pieces of leather for cleaning the blocks and cotton gloves for touching them. The gloves also prevent heating up the block by the warm hand. Tungsten Carbide is a hard metal, heavy, high density. A steel with less ageing, but not so less ageing as ceramic. The Tungsten Carbide has very less oxidation.
Wolfram Karbid Tungsten Grade 0 Wolfram Carbid Hartmetall
Expansion temperature cofficient 4.23*10-6/°C at 20°C

for comparison:
Aluminium 21 to 25, Stainless steel 10 to 17, Copper 16, Brass 18, Steel 12, Titanium 9, Plastics 40-120

Tungsten should be used close to 20°C, because the material of most common workingpieces has a higher temperatue coefficient.
Grade 0 is a precision grade with high accuracy. A Tungsten Carbide Gauge Block should be useful for a very long time. I observed Tungsten has less ageing than a steel block.

Tungsten has a quality one step behind cera-blocks, but in general more reliable than steel blocks. Consider also Tungsten is very hard, be careful when touching a metal working piece, can create marks, similar material to milling tools. NormalyTungsten blocks are more expensive than steel blocks.
Typical grey color of Tungsten hard metal. Very less Vaseline or Balistol is enough for a Tungsten block. The polished and lapped side shines with intensity.

Steel Gauge Block Set

Steel Gauge Block Set Stahlendmaße Steel Grade 1 large 90mm gauge
Steel Gauge Block Set
polished with shellac
Inside with a leather and a linen for cleaning Accuracy Grade 1 is a class lower compared to 0 Steel Gauge up to 90mm
The steel gauge block is useful when working on steel workpieces, both metals having a similar thermal expansion coefficient. Therefore the ambient temperature coefficient cancels out even when used under 15°C or 30°C, so far the TC is similar. Steel is softer compared to Tungsten Carbid.

Steel require after use Vaseline or Ballistol, but should be removed before use, a disadvantage compared to ceramic blocks. Use also gloves to reject thermal expansion caused by the hand heat. I observed this with old steel gauge set, some of the blocks are shrinked a little bit (not much) compared to the cera block reference. Steel gauge blocks require sometimes a calibration to check their accuracy, especially in an unknown condition or after byuing a second hand set with unknown history. Ageing is a topic for steel block sets, but I can`t say if modern steel quality behave the same, ageing of steel is known since decades, depends much on the method the steel has been manufactured. In comparison measurents my Tungsten set is closer to cera block set than the steel set. A safe statement can only be done after controlled calibrating with known standards.

Many measurement errors appearing caused by the user (not cleaned, temperature difference, not used at 20°C). Consider also the application and in my case a hobbiest 100kg CNC milling machine, currently used without precision collets in the spindle - the steel ageing is absolutely not a problem in the accuracy range of my metal equipment. Anyway with the ceramics a fine reference at home. These old unknown condition steel is fine for using in "rough applications with less accuracy" where to prevent the ceramics from a damage. It is the same when choosing at home between 20 oscilloscopes, you always choose the one suitable for the task.

Optical flat glass

Optical flat planglas with large diameter text text
Optical flat glass from CCCP this planglass has a large diameter 120mm, not often seen I wished I could read this language
flat planes Glas
another type from Japan small size
With a optical flat you can test a polished. lapped metal surface if it is very flat. This test require a light source with one wavelenght and the glass. Optical flat used for producing fringes from a monochromatic lightsource, e.g. a laser light, sodium light, but also works with sunlight or daylight floescent lamps. With a monochromatic wavelenght light source it more easy to see the fringes. The web is full of information how this technology works.

Lapping plate

lapping plate made on a precision lathe machine
used for lapping a flat metal surface

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