Pneumatics|Automation|Published Nov 12, 2026|12 MIN READ
Which Filter Element Fits My SMC Air Filter? An AF Series Checklist for Element Changes
To find the right element for an SMC AF air filter, read the full model number on the filter. The body size in that number points to the element, such as AF40P-060S for a size 40 AF-D filter with the standard 5 µm rating. SMC recommends replacing the element every 2 years or when the pressure drop reaches 0.1 MPa, whichever comes first. Before you switch to a different filtration rating, such as a 40 µm element, confirm the exact part number with technical support, because a coarser element changes what reaches your valves and cylinders.
This post pairs with our seal kit checklist for SMC cylinders. Clean, dry air helps protect the seals and valves downstream, and the filter element is what keeps it that way. Questions about replacement elements for SMC AF filters come up often in tickets and live chats, usually about which element fits a filter and whether a different filtration rating will work.
Will a 40 µm Element Fit the Same Housing?
Which Element Do I Order for This Filter?
When Should the Element Be Changed?
1. What Is the Full Model Number?
The model number is printed on the filter body. Copy all of it, including the thread code, options and any suffix, because the same body size can come with different bowls, drains and series versions.
Not Sure What You Have?
If the label is worn, send photos of the body, bowl and label. A filter and a mist separator can look the same from the outside.
2. Which Series and Size Is It?
AF air filters, AFM and AFD mist separators and AW filter-regulators look alike, but they are different products. SMC lists replacement elements for AF filters and AW filter-regulators separately from the element assemblies for AFM and AFD mist separators. For an AF-D filter, the body size points to the standard element:
| Filter | Body Size | Standard Element (5 µm) |
|---|---|---|
| AF20-D | 20 | AF20P-060S |
| AF30-D | 30 | AF30P-060S |
| AF40-D | 40 | AF40P-060S |
| AF50-D | 50 | AF50P-060S |
| AF60-D | 60 | AF60P-060S |
3. What Filtration Rating Do You Need?
SMC's standard AF element has a nominal filtration rating of 5 µm. Proax also lists rating variants for each size, coded at the end of the part number. For size 40, AF40P-060S-7-2B, -10B, -20B, -40B, -70B and -100B cover 2 to 100 µm, and AF40P-060S-7-5S is a sintered stainless steel element. The AF50P-060S-7-40B, for example, is a 40 µm element for size 50. Before you switch, confirm with technical support that the element fits your exact filter and suits the application.
Standard Element
A non-woven fabric element that removes particles down to 5 µm, the standard rating for AF filters.
Coarser Element
Lets larger particles through to the valves, cylinders and seals downstream. Confirm fit and suitability before you order.
Not a Like-for-Like Swap
Changing the filtration rating changes what reaches the equipment downstream. If the line feeds precision valves or a mist separator, check the air quality those parts need first.
4. When Should You Replace the Element?
SMC recommends replacing the element every 2 years, or when the pressure drop since initial operation reaches 0.1 MPa, whichever comes first. Leaving it longer can damage the element.
If liquid in the bowl reaches the baffle, drain the bowl and replace the element.
5. How Do You Replace It Safely?
Release the Pressure
Make sure no pressure remains in the filter before you remove the bowl.
Remove the Bowl
Hold the lock button, rotate the bowl about 30 degrees, line up the marks and pull it down.
Change the Element
The steps differ by size. On the AF50-D and AF60-D, remove the baffle to release the element. Follow the manual for your size.
Check for Leaks
Refit the bowl, restore pressure and check for leaks before returning the filter to service.
Drain With Pressure On
SMC notes that drain will not discharge properly unless the filter is pressurized. With N.C. auto drains, drain any remaining liquid by hand at the end of each working day.
6. Should You Replace Other Parts at the Same Time?
SMC also lists bowl assemblies, bowl seals and auto drains as replacement parts for each size. If the bowl or drain is damaged, replace it while the filter is open, using the part number for your exact model.
7. Is the Element Available When You Need It?
Ask Proax to check current availability for the element and any other parts, or use the SMC element configurator on proax.ca to build the part number for your filter size.
Where the SMC AF Filter Fits
The SMC AF air filter removes solid particles and water droplets from compressed air before it reaches regulators, valves and actuators. Keeping its element in good condition is one of the simplest parts of pneumatic maintenance.
5 µm Standard
Non-woven fabric element with a 5 µm nominal filtration rating.
Sizes 20 to 60
AF-D bodies from 1/8 to 1 in ports, with a matching element for each size.
Service Indicator
Option L shows when the element needs replacing.
Auto Drain
Float-type N.C. or N.O. auto drain options.
Bowl Options
Polycarbonate, metal, nylon or metal with a level gauge.
Service Interval
Replace every 2 years or at a 0.1 MPa pressure drop.
Sources: SMC AF20-D to AF60-D air filter, SMC AF-D operation manual and SMC replacement element for AF filters.
When to Call Technical Support Before Ordering
- The Label Is Worn or Missing
- The Filter Is an Older or Special Version
- You Want a Different Filtration Rating
- The Model Includes a Made-to-Order Code
- The Line Feeds a Mist Separator or Precision Equipment
Checklist: What to Gather Before You Contact Proax
An Element Order Goes Faster With This Information:
Not Sure Which Element Fits?
Send your filter's model number and label photos, and our in-house team will help you find the right element and check lead times.
