Magnaflux 20B Fluorescent Magnetic Particle Premix

Premix powder for fluorescent water-bath magnetic particle testing

Magnaflux 20B is a fluorescent magnetic particle premix powder for making a water-based wet-method bath. It combines the manufacturer’s 14A magnetic particles with corrosion inhibitors and wetting agents, so a single powder gives bright fluorescent green indications under UV black light together with surface wetting and corrosion protection. The sheet describes it as highly sensitive for fine discontinuities in high-volume applications such as forging, casting, stamping and welding.

It is positioned for baths that are changed frequently because of drag-in or heavy use, and for in-process testing to detect cracks, seams, inclusions, laps, tears and flakes. The data sheet says 20B meets major industry and NDT specifications, including automotive, API and ASTM standards.

Features

• Premix of 14A particles, water conditioners and corrosion preventatives
• Designed to mix with water at low concentrations for performance and economy
• Non-foaming, easily dispersed and good concentration consistency
• Good surface wetting and dispersion stability
• Easy post-test cleanup
• Suitable for steel, iron alloys and nickel alloys

Technical specification

Ordering guide and mixing ratio

The printed mixing ratio is 1.5 ounces of 20B per gallon of water, or 11.2 grams per litre, and a measuring scoop in the container measures enough 20B for one gallon. Derived value: a 15 lb (240 oz) pail makes about 160 gallons of bath at that ratio, and a 1 lb jar about 10.7 gallons; these are our own calculations from the printed ratio.

Preparation, use and maintenance

Fill the tank with water. Weigh or measure the powder, add a small amount of water to form a thick paste, then add the paste to the tank and mix for at least 15 minutes until the particles are evenly dispersed. Warm water at about 38 C (100 F) helps the powder mix faster. Never mix 20B with petroleum distillate.

The suspension is applied by gentle spraying or flooding, using the continuous or residual method, and inspected under black light. Check concentration after preparation and at least daily with an ASTM pear-shaped centrifuge tube; the sheet recommends the Magnaflux tube 8493. 20B is hygroscopic, so keep containers tightly sealed, cool and dry and protect from sunlight.

Applications

Named uses are castings, forgings, stamped parts and ferromagnetic metals, with high volume testing, smooth surface finishes, post-secondary-processing and in-service inspection. In the region, wet benches in foundries, fastener and valve manufacturing and heavy repair shops are the likely users, with the bath replaced often to suit drag-in of oil and dirt.

20B compared with 14AM: powder for water or ready-made oil

Both products carry Magnaflux 14A particles and give the same printed particle size range and SAE sensitivity. The difference is the carrier and the work routine, shown from the two data sheets.

A water bath costs little per litre and is normal in high-volume lines where parts are washed and the bath is renewed often. An oil bath needs less maintenance per the 14AM sheet and avoids water-related corrosion on parts that wait before further processing. This reading of the two sheets is ours; the governing procedure decides which carrier is allowed.

Planning a water-bath line with 20B

Because 20B is a powder, it is used to make a bath on site, so the planning list differs from the ready-made products. You need clean water, a tank with agitation, a scale or the supplied scoop, a settling tube for daily checks, a magnetising device and a UV light with a darkened inspection area. The printed ratio of 1.5 ounces per gallon, or 11.2 grams per litre, sets the starting concentration, and the settling volume range of 0.10 to 0.40 mL is the figure to check against.

Storage and handling

The sheet notes that 20B is hygroscopic, so keep jars and pails tightly sealed, cool and dry at 10 to 30 C, and protect them from sunlight. Reseal the container immediately after taking powder, because moisture causes lumping that makes the bath hard to mix. Use the Safety Data Sheet for protective equipment, especially for dust when handling the dry powder.

Information needed for a quotation

Send the part number from the ordering table, the number of jars or pails, the delivery location in Oman or the GCC and any specification the shipment must reference. If a UV lamp or a settling tube is also needed, add it to the same request so that the whole station can be quoted together.

Related items

For a ready-made oil bath see 14AM; for visible aerosol see 7HF; the Y-7 yoke handles portable inspection. Browse the Non-Destructive Testing (NDT) category for more.

Related Magnaflux products: Magnaflux 7HF Oil-Based Visible Magnetic Particle Aerosol, Magnaflux ZL-60D Level 2 Water Washable Fluorescent Penetrant, Magnaflux ZL-67 Level 3 Water Washable Fluorescent Penetrant, Magnaflux Y-7 AC/DC Electromagnetic Yoke, Magnaflux SKC-S Spotcheck NDT Cleaner and Remover and Magnaflux ZP-9F Solvent Based Developer Aerosol.

Documents and quotation

The official data sheet is hosted on this page. Confirm the pack size and specification list before ordering; Seven Star LLC is an independent supplier in Muscat and answers RFQs with the part number.