A.Y. McDonald 21000 Series J - 5 GPM 4" No-Lead Brass Submersible Pump, 1/2-1.5 HP
A.Y. McDonald 21000 Series K - 10 GPM performance curve: total head vs flow by horsepower, Pumps by Baker catalog p. 30
A.Y. McDonald 21000 Series J - 5 GPM 4" No-Lead Brass Submersible Pump, 1/2-1.5 HP
A.Y. McDonald 21000 Series K - 10 GPM performance curve: total head vs flow by horsepower, Pumps by Baker catalog p. 30

A.Y. McDonald 21000 Series K - 10 GPM 4 in No-Lead Brass Submersible Pump

HP - Motor Dia: 1/2 HP - 4 in Motor
Voltage - Phase: 115V 1Ph 2-Wire
Model - Head: 21050K2A - 171 ft at 10 GPM

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$909.85
SKU: 6650-009
Weight : 29.0 lb
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Description
A.Y. McDonald · Submersible Well Pump
21000 Series K - 10 GPM
No-Lead Brass 4 in submersible pump on a Baker motor, 1/2 to 5 HP, 16 builds.
171-864 ft at 10 GPM
1/2-5 HP
115V or 230V 1Ph · 230V 3Ph
1331 ft Max Head (Shut-off)
1 1/4 in NPT Discharge
Built-In Check Valve
Baker 4 in Stainless Steel Motor
3 3/4 in Dia x 24.2-63.9 in L
27-97 lb Weight
What Ships and What It Needs to Run

Included: the pump end and Baker 4 in motor with leads, assembled as one complete pump, with the internal check valve and a grounded lead on the motor.

Two-wire builds: the controls are in the motor, so no control box is needed.

Three-wire single-phase builds: the control box is included.

Three-phase builds: the starter kit is included.

Drop cable and splice kit: sized to your setting depth and ordered separately.

Overview

The 21000 Series is Baker’s no-lead brass 4 in submersible pump, built in six flow classes: 5, 7, 10, 15, 20 and 25 GPM. Each pump ships assembled on a Baker stainless steel motor, with a no-lead brass discharge head and built-in check valve, and a stainless steel shaft and coupling.

Baker builds the stack with its captured stack design: sand notches in the diffusers keep sand moving through the pump. Each pump is individually tested after assembly and stamped with the tester’s mark.

This listing is the K - 10 GPM class: 1/2 to 5 HP, 16 builds, two-wire up to 1 1/2 HP and three-wire up to 5 HP, all with a 1 1/4 in NPT discharge.

  • Check valve — acetal poppet and seal housing, Buna-N O-ring and stainless steel retention screw; threaded for easy installation or removal; working pressure 400 PSI.
  • Discharge casting and motor bracket — no-lead brass alloy.
  • Discharge bearing — rubber around the stainless steel shaft; self-lubricating, holds shaft alignment.
  • Diffusers — polycarbonate, corrosion and abrasion resistant, built for sand handling.
  • Impellers — glass bead acetal.
  • Shaft — 7/16 in 300 series stainless steel, hex drive, each one measured for straightness.
  • Shell — polished stainless steel, threaded at both ends for field service.
  • Cable guard — stainless steel; angled top keeps the leads in place while the pump is lowered or raised.
  • Motor coupling — stainless steel.
  • Intake screen — non-corrosive.
Genuine A.Y. McDonald equipment, factory-new in original packaging — sold and supported by Watermain Supply, an independent industrial supplier. Watermain Supply is an Authorized Stocking A.Y. McDonald and Baker Water Systems Distributor.
5-Year A.Y. McDonald Warranty in Potable Water

Covered for 5 years from the date of manufacture in potable water applications, and 3 years from the date of manufacture in other applications, under A.Y. McDonald’s published terms for Baker submersible motors and assembled submersible pumps (pump ends up to 25 GPM for the 5-year term, up to 80 GPM for the 3-year term).

Room to Grow

One pump per well. Need more head later? Step up in horsepower within the K - 10 GPM class. Need more flow? Move to a higher flow class of the 21000 Series, which runs to 25 GPM; every class uses the same 1 1/4 in NPT discharge, so the drop pipe connection stays the same.

Shared Specifications
Included Pump end, motor and leads; control box on three-wire single-phase builds; starter kit on three-phase builds
Discharge 1 1/4 in NPT (female)
Pump diameter 3 3/4 in with cable guard
Well size 4 in and larger
Check valve Built in
Motor Baker 4 in stainless steel submersible motor, NEMA 4 in flange, IP68, insulation class F
Motor temperature rating 95°F
Cooling flow past the motor 1.0 ft/sec at 95°F
Maximum starts 20 per hour
Maximum operating depth (motor) 984 ft
Voltage tolerance +6% / -10%
Frequency 60 Hz
App connection None; the pump runs from its own controls

Motor data: Pumps by Baker catalog (Sept 2025, rev 3/26), pp. 121-128.

Models & Performance — Will It Do What You Need?

Find your horsepower in the row, then read across. Total head is the lift from the pumping water level to the discharge, plus the pressure you want at the tank (2.31 ft for every PSI), plus friction in the drop pipe.

Total head in feet · curves end at 20–21 GPM

HP 0 GPM (Shut-off) 4 GPM 11 GPM 16 GPM 20 GPM
1/2 HP 259 ft 233 ft 157 ft 87 ft 26 ft
3/4 HP 333 ft 304 ft 207 ft 122 ft 38 ft
1 HP 448 ft 394 ft 288 ft 167 ft 50 ft
1 1/2 HP 591 ft 526 ft 365 ft 209 ft 53 ft
2 HP 758 ft 672 ft 450 ft 257 ft 48 ft
3 HP 1042 ft 904 ft 618 ft 358 ft 113 ft
5 HP 1331 ft 1166 ft 802 ft 454 ft 124 ft

Read from the published curve in the Pumps by Baker catalog (Sept 2025, rev 3/26), p. 30, digitized and rounded down, at the flows nearest 20%, 50% and 75% of the curve’s 21.2 GPM end. 0 GPM is the printed shut-off. The last column is the last flow every curve reaches; the curve ends are named in the table title.

Output in GPM at 30 PSI (switch cut-in), by depth to water

HP 25 ft 50 ft 100 ft 150 ft 200 ft 250 ft 300 ft
1/2 HP 15.77 14.09 10.28 5.44 — — —
3/4 HP 17.20 15.97 13.28 10.21 6.54 1.61 —
1 HP 18.56 17.68 15.82 13.81 11.59 9.10 6.18
1 1/2 HP — 18.46 17.15 15.76 14.29 12.72 11.01
2 HP — 18.51 17.49 16.44 15.35 14.21 13.02
3 HP — 19.97 19.17 18.35 17.51 16.65 15.77
5 HP — 20.17 19.59 18.99 18.39 17.77 17.14

Output in GPM at 50 PSI (switch cut-out), by depth to water

HP 25 ft 50 ft 100 ft 150 ft 200 ft 250 ft 300 ft
1/2 HP 12.56 10.60 5.87 — — — —
3/4 HP 14.86 13.49 10.46 6.85 2.07 — —
1 HP 16.91 15.97 13.97 11.77 9.30 6.42 2.83
1 1/2 HP — 17.25 15.87 14.41 12.84 11.15 9.29
2 HP — 17.57 16.52 15.44 14.30 13.11 11.87
3 HP — 19.23 18.41 17.58 16.72 15.84 14.94
5 HP — 19.63 19.04 18.43 17.82 17.19 16.54

Output tables as printed in the Pumps by Baker catalog (Sept 2025, rev 3/26), pp. 29-30, at the 30 and 50 PSI rows. Riser-pipe friction is not included (manufacturer note): add it for long or small drop pipe. — marks a point A.Y. McDonald does not print for that horsepower.

Best operating range: the published curve shades the most efficient operating range for each model; the catalog prints no figures for it. The curve is in the image gallery.

Before You Buy — The Limits That Decide the Fit
Well size 4 in casing and larger; the pump is 3 3/4 in diameter with the cable guard
Power Two-wire builds need no control box (the controls are in the motor); three-wire single-phase builds include their control box; three-phase builds include their starter kit. Match voltage and phase to your service; single-phase and three-phase builds are not interchangeable
Water temperature Motor rated to 95°F
Motor cooling 1.0 ft/sec of water flow past the motor at 95°F
Starts Up to 20 starts per hour
Setting depth Motor rated to 984 ft operating depth
Riser friction Not included in the output tables; add it before choosing
Application Water wells; the manufacturer excludes use in swimming areas
Pairing One pump per well
Materials of Construction
Check valve Acetal poppet and seal housing, Buna-N O-ring and stainless steel retention screw; threaded for easy installation or removal; working pressure 400 PSI
Discharge casting and motor bracket No-lead brass alloy
Discharge bearing Rubber around the stainless steel shaft; self-lubricating, holds shaft alignment
Diffusers Polycarbonate, corrosion and abrasion resistant, built for sand handling
Impellers Glass bead acetal
Shaft 7/16 in 300 series stainless steel, hex drive, each one measured for straightness
Shell Polished stainless steel, threaded at both ends for field service
Cable guard Stainless steel; angled top keeps the leads in place while the pump is lowered or raised
Motor coupling Stainless steel
Intake screen Non-corrosive

Construction as described by the manufacturer. Source: Pumps by Baker catalog (Sept 2025, rev 3/26), pp. 23-24.

For engineering-led sizing and selection support or a factory submittal, email sales@watermainsupply.com or call 1-888.510.4036.
© Watermain Supply — A division of E4 Industrial LLC
Data Sheet
Pumps by Baker 21000 Series Guide
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