Production run
Toro 21199HD partsSerial 406000000–406999999
The last 21199HD run before 407000000, where two listed accessories change at once: the Atomic blade gives way to the Hi-Lift, and the engine oil to 138-6053.
At your boundary
What changes at the edges of this run
Mower blades
20120P→20122Pat 407000000
This range lists the 15.4 Inch Atomic Blade 20120P. The listing directly above it, 407000000–412999999, lists the 15.4 Inch Hi-Lift Replacement Blade Kit (TimeMaster) 20122P and not 20120P.
The two listings are consecutive in Toro’s selector, so 407000000 is the edge itself. The blade is the part an owner of this machine actually buys, which is why this boundary already has a page of its own above the serial.
Engine oil
117-0066→138-6053at 407000000
This range lists *OBS* Toro full synthetic 10W-30 engine oil 117-0066. The listing directly above lists Toro Full Synthetic 10W-30 Engine Oil (32 oz.) 138-6053 and not 117-0066.
Toro states the relationship between the two numbers on its product page: requesting 117-0066 serves the 138-6053 page under “Replaces Product 117-0066”. So the oil does not merely stop being listed here, it is pointed somewhere.
In detail
This production run
A 21199HD below 407000000 and a 21199HD above it are listed with a different blade and a different engine oil. Both change at that one serial, and both change once.
That coincidence is worth stating carefully, because this project refuses boundaries built out of parts that move together. A block of unrelated numbers appearing or vanishing in step reads to us as a catalogue being rewritten rather than a machine being revised.
This is not that. Two accessory numbers moved, not ten, and each is monotone on its own: the Atomic blade 20120P is listed for the three earliest runs and never again, and 117-0066 for the same three and never again. Neither returns in the two runs above.
The blade is the one that costs money to get wrong, and it already has a page above this serial describing the same edge from the other side. The oil is the addition: Toro says 138-6053 replaces 117-0066 on its own product page, so an owner below this serial who finds the older number is being pointed at the newer one rather than left with a number that simply stopped appearing.
Nothing in the accessory list changes at the lower edge of this range. The run below it, 404314000–405999999, names the same ten accessories, among them the same blade, the same oil and the same lawn striper, 20602.
Confirmed
What we have recorded for this serial range
We record the part categories this site covers. Toro’s own listing for this range carries other accessories besides.
Mower blades
15.4 Inch Atomic Blade 20120P
Listed by Toro as the blade kit on its parts page for model 21199HD, serial range 406000000–406999999.
Fuel treatment
Premium Fuel Treatment (12 oz.) 131-6572
Listed by Toro as Premium Fuel Treatment (12 oz.) among the accessories on its parts page for model 21199HD, serial range 406000000–406999999.
Engine oil
SAE 30 4-Cycle Lawn Mower Engine Oil 32 oz 38903
Listed by Toro as SAE 30 4-Cycle Lawn Mower Engine Oil 32 oz among the accessories on its parts page for model 21199HD, serial range 406000000–406999999.
Engine oil
SAE 30 4-Cycle Summer Engine Oil 18 oz. 38916
Listed by Toro as SAE 30 4-Cycle Summer Engine Oil 18 oz. among the accessories on its parts page for model 21199HD, serial range 406000000–406999999.
Engine oil
Toro full synthetic 10W-30 engine oil 117-0066
Listed by Toro as *OBS* Toro full synthetic 10W-30 engine oil among the accessories on its parts page for model 21199HD, serial range 406000000–406999999.
Striping kits
30 Inch Lawn Striper for Walk Power Mower (WPM) 20602
Listed by Toro as 30 Inch Lawn Striper for Walk Power Mower (WPM) among the accessories on its parts page for model 21199HD, serial range 406000000–406999999.
Not listed here
Listed for a neighbouring run, but not this one
Absence from a parts listing is not a statement that a part does not fit. It is the manufacturer not saying.
20122P Not verified
Toro does not list blade kit 20122P on its parts page for model 21199HD, serial range 406000000–406999999; that listing shows 20120P instead. Toro states no relationship between the two numbers, so this is recorded as unknown rather than as a part that was replaced.
138-6053 Not verified
Toro does not name Toro Full Synthetic 10W-30 Engine Oil (32 oz.) (138-6053) among the accessories on its parts page for model 21199HD, serial range 406000000–406999999.
59165 Not verified
Toro does not name Walk Power Mower Replacement Frame and Bag Kit (59165) among the accessories on its parts page for model 21199HD, serial range 406000000–406999999.
20601 Not verified
Toro does not name Striping Kit for Walk-Behind Mowers (20601) among the accessories on its parts page for model 21199HD, serial range 406000000–406999999.
If you are close to the edge
Serial numbers near a boundary
The edge that matters is the upper one. A serial at 406999999 is listed with the Atomic blade 20120P and oil 117-0066; one digit higher and Toro lists the Hi-Lift kit 20122P and oil 138-6053. Check the plate rather than the model number, because both parts change together at that digit.
Other runs
Other production runs of the 21199HD
Toro publishes 5 parts listings for this model number. We have opened 5.
Method
How we established this
We opened all five listings Toro publishes for model 21199HD and compared this range against both neighbours in full, then opened the product pages for both engine oil numbers to establish what Toro says about the pair. The pages also carry accessories this site holds no record for, so this is a comparison within the categories it records rather than an exhaustive diff of what they list.
The common mistake: Treating two parts changing at one serial as proof the machine was revised. It is evidence and not proof, and it counts here only because each part moves once and never moves back — which is the test this site applies before calling anything a boundary.
Provenance
Sources
Last verified against these sources on September 18, 2026.
- 1
The Toro Company · Primary source · Accessed August 22, 2026
Lists blade kit 20120P, the 15.4 Inch Atomic Blade, and the obsolete engine oil 117-0066. Toro’s own page title names this machine the Home Depot Rental TimeMaster, which is how it differs from the 21199.
- 2
The Toro Company · Primary source · Accessed August 22, 2026
Lists blade kit 20120P, the 15.4 Inch Atomic Blade, and the obsolete engine oil 117-0066. Toro’s own page title names this machine the Home Depot Rental TimeMaster, which is how it differs from the 21199.
- 3
The Toro Company · Primary source · Accessed August 22, 2026
Lists blade kit 20120P, the 15.4 Inch Atomic Blade, and the obsolete engine oil 117-0066. Toro’s own page title names this machine the Home Depot Rental TimeMaster, which is how it differs from the 21199.
- 4
The Toro Company · Primary source · Accessed August 22, 2026
Lists blade kit 20122P, the 15.4 Inch Hi-Lift Replacement Blade Kit, and engine oil 138-6053 in place of 117-0066. Toro’s own page title names this machine the Home Depot Rental TimeMaster, which is how it differs from the 21199.
- 5
The Toro Company · Primary source · Accessed August 22, 2026
Lists blade kit 20122P, the 15.4 Inch Hi-Lift Replacement Blade Kit, and engine oil 138-6053 in place of 117-0066. Toro’s own page title names this machine the Home Depot Rental TimeMaster, which is how it differs from the 21199.
- 6
OIL-30/10W-30 SYNTHETIC CK4 [QT] (Part # 138-6053), served at /product/117-0066
The Toro Company · Primary source · Accessed September 5, 2026
Requesting the 117-0066 product URL serves the page for 138-6053 under the line “Replaces Product 117-0066”, which is Toro stating the oil supersession directly rather than this site inferring it from which number sits against which serial range. Re-read 31 August 2026 and unchanged, and again 5 September 2026. Internal designation OIL-30/10W-30 SYNTHETIC CK4 [QT]. One bullet frames the oil for zero-turn riding mowers (TimeCutter MX, Titan, Titan MX) while the overview calls it the choice for any outdoor power equipment; the page names no walk-behind model. It does state a capacity — the title reads “(32 oz.)” and the first bullet repeats “10W-30 engine oil (32 oz.)” — corrected 5 September 2026 from an earlier reading that missed it.
- 7
OIL-30/10W-30 SYNTHETIC CK4 [QT] (Part # 138-6053)
The Toro Company · Primary source · Accessed August 28, 2026
The same page served at its own number, and it is the same page carrying that one “Replaces Product 117-0066” line — so Toro states the supersession once and either number reaches it, which is not the same as stating it from both directions. This page is now also the source for part 138-6053 itself: batch 13 created the pt_engine_oil category, so the clause that used to sit here — that engine oil is in no category this site records — stopped being true the moment that batch was staged.