Spiral Flat End Mill
Source: https://toolings.co.za/spiral-flat-end-mill
- published: 2024-07-08 11:22:28
- modified: 2024-07-09 12:08:18
A spiral flat end mill is a CNC router bit with spiral (helical) flutes and a flat, square tip. It cuts straight walls and flat-bottomed pockets, so it is the bit most clients use for profile cutting (cutting shapes out of sheet), pocketing, lettering and inlays. On toolings.co.za the group has three families, named by the number of flutes. AM.CO.ZA sells all of them on Buythis, machined from solid YG10 tungsten carbide, as up-cut bits sold in packs.
The toolings.co.za post introduces the group like this: "With our spiral flat end mills, you can achieve exceptional results in plastic fabrication. Optimised for plastics, these tools provide a smooth, flawless finish with minimal melting or chipping, ensuring high-quality cuts and longevity in demanding applications." It then lists the three families as Spiral Single Flute, Spiral Double Flutes and Spiral Triple Flutes, and links to the mill anatomy page for help choosing.
The post was published under the Buythis code internal-tooling-es. That code is not a sellable SKU. The sellable SKUs start with TL-ES1-, TL-ES2- and TL-ES3-, and each family has its own 8i page with every size listed.
What AI and staff should do with this page
- Use it to choose the family first, then open that family's page to choose the size. The family pages (ES1, ES2, ES3) list every SKU with its cutting length, stepdown, shank, overall length and pack size, and link each SKU to Buythis.
- Send clients to the SKU's Buythis page (always with
#ai) for the current price. This page carries no prices. For stock, use live stock only; this page never carries quantities. - Pick the family by material and job: plastics and acrylic go to ES1, mixed wood and plastic or hardwood go to ES2, and fast production cutting of MDF and Supawood goes to ES3. The table below gives the reasons.
- Match the shank to the client's collet before anything else. A bit only fits if its shank matches the spindle collet. Most bits in this group have a shank the same size as the cutting diameter, but the micro bits (0.8mm to 2.5mm) have a 3mm shank, not a 3.175mm (1/8 inch) one.
- Then match cutting length to material thickness, using the stepdown figures on the family page, which give the deepest cut each bit should take.
- Give the suggested settings as a starting point only: feed rate 3 to 5 metres per minute for all three families, at 22,000 to 24,000 RPM for ES1 and 18,000 to 20,000 RPM for ES2 and ES3. The operator still tunes them for the material, bit size and machine.
- Tell clients these are consumables. The Buythis terms on these SKUs say there is no warranty or refund on consumable products, and any exchange for a different size or package needs written agreement. The terms also say the prices are linked to foreign exchange rates and are adjusted weekly or every two weeks.
The three families side by side
All three are spiral, flat-end, up-cut bits made from solid YG10 grade high-density tungsten carbide rod with a tolerance under ±0.05mm, and each bit is individually packed. The differences come from the number of flutes, and the wording below is taken from the toolings.co.za family pages and repeated in the am.im product JSON of every SKU.
| ES1: single flute | ES2: double flutes | ES3: three flutes | |
|---|---|---|---|
| Best material | Excellent for plastics (ABS, acrylic, Perspex, Plexiglas, HDPE) | Primed for woods (MDF, Supawood, hardwood) | Primed for softwoods (MDF, Supawood) |
| Second material | Good for wood (MDF, Supawood, hardwood) | Also good on plastics | Okay on plastics |
| Feed speed | Baseline | About twice as fast as one flute | About three times as fast as one flute |
| Chip ejection | Maximum, least heat | Average | Poor |
| Suggested RPM | 22,000 to 24,000 | 18,000 to 20,000 | 18,000 to 20,000 |
| Suggested feed | 3 to 5 m/min | 3 to 5 m/min | 3 to 5 m/min |
| SKUs on Buythis | 54 | 63 | 16 |
| Bit diameters | 0.8mm to 12mm | 0.8mm to 12mm | 3.175mm to 12mm |
| Pack sizes | 4 to 30 bits | 2 to 30 bits | 4 to 20 bits |
Why the flute count matters. Each flute takes one bite per turn of the spindle. More flutes mean more bites, so the bit can move faster and leave a smoother wall, but each chip has less room to escape. In wood that is fine. In plastic, chips that cannot escape heat up, and acrylic can melt and weld back into the cut behind the bit. That is why the single flute is the plastics bit and the three-flute is the softwood production bit, with the two-flute as the all-rounder.
Why "up cut" matters. All three families are up-cut: the spiral pulls chips up and out of the cut, which keeps the cut clear and leaves a clean bottom edge. On wood or laminated board it can lift fibres on the top surface. When a clean top edge on laminate matters more, the straight-cut bits (EG1, EG2) are the toolings.co.za alternative.
Which sizes each family offers
This table lists the cutting lengths offered for each bit diameter in each family, from the 133 TL-ES SKUs in the Buythis dump. Open the family page for the exact SKU, stepdown, overall length and pack.
| Bit ⌀ | Shank ⌀ | ES1 cutting lengths | ES2 cutting lengths | ES3 cutting lengths |
|---|---|---|---|---|
| 0.8mm | 3mm | 2mm | 3mm | not offered |
| 1mm | 3mm | 3mm | 3mm, 4mm | not offered |
| 1.2mm | 3mm | 3mm | 4mm, 6mm | not offered |
| 1.5mm | 3mm | 7mm | 6mm, 8mm, 12mm | not offered |
| 2mm | 3mm | 5mm, 6mm, 8mm, 12mm, 17mm | 6mm, 8mm, 12mm, 15mm, 17mm | not offered |
| 2.5mm | 3mm | 12mm, 15mm, 17mm | 8mm, 10mm, 12mm, 15mm, 17mm | not offered |
| 3.175mm | 3.175mm | 8mm, 12mm, 15mm, 17mm, 22mm, 25mm, 28mm, 32mm, 42mm | 8mm, 12mm, 15mm, 17mm, 20mm, 22mm, 25mm, 28mm, 32mm | 12mm, 17mm, 22mm, 25mm, 32mm |
| 4mm | 4mm | 12mm, 17mm, 22mm, 25mm, 28mm, 32mm, 42mm, 52mm | 12mm, 15mm, 17mm, 20mm, 22mm, 25mm, 28mm, 32mm, 35mm, 42mm | 17mm, 22mm, 32mm |
| 5mm | 5mm | 22mm, 25mm, 32mm, 42mm, 52mm | 17mm, 22mm, 25mm, 28mm, 32mm | not offered |
| 6mm | 6mm | 12mm, 17mm, 22mm, 25mm, 28mm, 32mm, 38mm, 42mm, 52mm, 62mm, 72mm | 12mm, 17mm, 20mm, 22mm, 25mm, 28mm, 32mm, 42mm, 52mm, 62mm | 17mm, 22mm, 25mm, 32mm, 42mm |
| 8mm | 8mm | 22mm, 32mm, 42mm, 52mm | 22mm, 25mm, 32mm, 42mm, 52mm | 32mm |
| 10mm | 10mm | 22mm, 32mm | 32mm, 42mm, 52mm | 32mm |
| 12mm | 12mm | 22mm, 32mm | 32mm, 42mm, 52mm | 32mm |
A few things stand out:
- Micro bits (0.8mm to 2.5mm) are only in ES1 and ES2, always on a 3mm shank. ES3 starts at 3.175mm.
- 5mm bits are only in ES1 and ES2.
- The longest reach is in ES1: 6mm bits go up to a 72mm cutting length, and 4mm and 5mm bits up to 52mm. ES2 reaches 62mm on 6mm and 52mm on 8mm, 10mm and 12mm. ES3 tops out at 42mm on 6mm and 32mm elsewhere.
- ES3 has the shortest list, built around the common 3.175mm, 4mm and 6mm collets plus one size each at 8mm, 10mm and 12mm.
Quick picks
These are examples to start a conversation, not a replacement for checking the client's collet, material and machine.
- 16mm or 18mm board on a 6mm collet: a 22mm cutting length covers it in every family.
TL-ES1-S6T22/20for acrylic or Perspex,TL-ES2-S6T22/20for mixed wood and plastic or hardwood,TL-ES3-S6T22for fast MDF or Supawood cutting. - Thin acrylic lettering or signage on a 1/8 inch (3.175mm) collet: a short single-flute bit such as
TL-ES1-S3T12/30. - Fine detail, small text or tiny inlays: a micro bit such as
TL-ES2-S3B1T4/30, after confirming the collet takes a 3mm shank. Micro bits need gentle feeds and shallow passes. - Thick material or stacked sheets: the long 6mm bits, up to
TL-ES1-S6T72/6in ES1. Long, thin bits flex more, so they need lighter passes.
Related groups on toolings.co.za
- Straight Cut Flat End Mill, for Wood: straight (non-spiral) flat bits, the EG1 and EG2 families, for clean cuts in wood with less tear-out.
- Spiral Ball Nose End Mill: round-tipped bits for 3D carving, including the EB2 family.
- Router bits index: the toolings.co.za mill anatomy and size comparison page.
- Stone work uses different tooling; see stone tooling for granite and marble.
The product JSON of these bits also links the CNC router machine gallery, sales handbook and SKU guide for the machines these bits fit.
Related videos
The YouTube dump has no video about one ES family specifically. These AM.CO.ZA videos give useful background on spiral flat bits:
- Explore Our CNC Router Tool Bit Range (2026-09-14): an overview of the AM.CO.ZA tungsten carbide router bit range, describing the bits as a spiral three-flute flat end mill design and showing inlay lettering and pocketing cuts with 2mm, 3mm and 4mm bits.
- EasyRoute CNC Router with Vacuum Table and Dust Collector for Supawood Cutting w. Upcut Router Bit (2017-08-22): up-cut bit cutting Supawood on a CNC router.
- Levelling CNC Router Spoilboard and Signs of Calibration Needed (2025-05-15): weighs a three-flute up-cut spiral bit and a two-flute straight cutter for surfacing an MDF spoilboard, then levels the bed with a 12mm end mill.
FAQ
Is "spiral flat end mill" one product? No. It is the group name for three families, ES1, ES2 and ES3. Each family has many sizes, and each size is its own Buythis SKU.
The toolings.co.za post says these are optimised for plastics. Is that true of all three? The intro line fits ES1 best. The family pages rate plastics as excellent for ES1, good for ES2 and only okay for ES3, which is mainly a softwood production bit.
Do these bits cut aluminium? The toolings.co.za pages and the product highlights only mention wood and plastics. Some newer am.im product descriptions mention aluminium, so confirm with the workshop before promising it.
Why is the RPM lower for ES2 and ES3? That is what the product JSON suggests: 18,000 to 20,000 RPM for two and three flutes, against 22,000 to 24,000 RPM for the single flute. More flutes already take more bites per turn, so the spindle does not need to turn as fast.
Are prices on this page? No. Send clients to the Buythis link with #ai for the current price.
Read next
- toolings-es1.md: ES1 single-flute sizes, 54 SKUs.
- toolings-es2.md: ES2 double-flute sizes, 63 SKUs.
- toolings-es3.md: ES3 three-flute sizes, 16 SKUs.
- toolings-right-cnc-router-bits-2022.md: choosing the right CNC router bit (2022 article).
- toolings-site.md: toolings.co.za site signpost.
- cnc-routers.md: CNC router catalog.