The women begin to arrive just before 8 a.m., every day and without fail, until there are thickets of young Asian and Hispanic women on nearly every street corner along the main roads of Flushing, Queens.

As if on cue, cavalcades of battered Ford Econoline vans grumble to the curbs, and the women jump in. It is the start of another workday for legions of New York City’s manicurists, who are hurtled to nail salons across three states. They will not return until late at night, after working 10- to 12-hour shifts, hunched over fingers and toes.

On a morning last May, Jing Ren, a 20-year-old who had recently arrived from China, stood among them for the first time, headed to a job at a salon in a Long Island strip mall. Her hair neat and glasses perpetually askew, she clutched her lunch and a packet of nail tools that manicurists must bring from job to job.

Tucked in her pocket was $100 in carefully folded bills for another expense: the fee the salon owner charges each new employee for her job. The deal was the same as it is for beginning manicurists in almost any salon in the New York area. She would work for no wages, subsisting on meager tips, until her boss decided she was skillful enough to merit a wage.

It would take nearly three months before her boss paid her. Thirty dollars a day.

Once an indulgence reserved for special occasions, manicures have become a grooming staple for women across the economic spectrum. There are now more than 17,000 nail salons in the United States, according to census data. The number of salons in New York City alone has more than tripled over a decade and a half to nearly 2,000 in 2012.

But largely overlooked is the rampant exploitation of those who toil in the industry. The New York Times interviewed more than 150 nail salon workers and owners, in four languages, and found that a vast majority of workers are paid below minimum wage; sometimes they are not even paid. Workers endure all manner of humiliation, including having their tips docked as punishment for minor transgressions, constant video monitoring by owners, even physical abuse. Employers are rarely punished for labor and other violations.

Asian-language newspapers are rife with classified ads listing manicurist jobs paying so little the daily wage can at first glance appear to be a typo. Ads in Chinese in both Sing Tao Daily and World Journal for NYC Nail Spa, a second-story salon on the Upper West Side of Manhattan, advertised a starting wage of $10 a day. The rate was confirmed by several workers.

Lawsuits filed in New York courts allege a long list of abuses: the salon in East Northport, N.Y., where workers said they were paid just $1.50 an hour during a 66-hour workweek; the Harlem salon that manicurists said charged them for drinking the water, yet on slow days paid them nothing at all; the minichain of Long Island salons whose workers said they were not only underpaid but also kicked as they sat on pedicure stools, and verbally abused.

Last year, the New York State Labor Department, in conjunction with several other agencies, conducted its first nail salon sweep ever — about a month after The Times sent officials there an inquiry regarding their enforcement record with the industry. Investigators inspected 29 salons and found 116 wage violations.

Among the more than 100 workers interviewed by The Times, only about a quarter said they were paid an amount that was the equivalent of New York State’s minimum hourly wage. All but three workers, however, had wages withheld in other ways that would be considered illegal, such as never getting overtime.

The juxtapositions in nail salon workers’ lives can be jarring. Many spend their days holding hands with women of unimaginable affluence, at salons on Madison Avenue and in Greenwich, Conn. Away from the manicure tables they crash in flophouses packed with bunk beds, or in fetid apartments shared by as many as a dozen strangers.

Ms. Ren worked at Bee Nails, a chandelier-spangled salon in Hicksville, N.Y., where leather pedicure chairs are equipped with iPads on articulated arms so patrons can scroll the screens without smudging their manicures. They rarely spoke more than a few words to Ms. Ren, who, like most manicurists, wore a fake name chosen by a supervisor on a tag pinned to her chest. She was “Sherry.” She worked in silence, sloughing off calluses from customers’ feet or clipping dead skin from around their fingernail beds.

At night she returned to sleep jammed in a one-bedroom apartment in Flushing with her cousin, her cousin’s father and three strangers. Beds crowded the living room, each cordoned off by shower curtains hung from the ceiling. When lights flicked on in the kitchen, cockroaches skittered across the counter-tops.

Almost all of the workers interviewed by The Times, like Ms. Ren, had limited English; many are in the country illegally. The combination leaves them vulnerable.

Some workers suffer more acutely. Nail salons are governed by their own rituals and mores, a hidden world behind the glass exteriors and cute corner shops. In it, a rigid racial and ethnic caste system reigns in modern-day New York City, dictating not only pay but also how workers are treated.

Korean workers routinely earn twice as much as their peers, valued above others by the Korean owners who dominate the industry and who are often shockingly plain-spoken in their disparagement of workers of other backgrounds. Chinese workers occupy the next rung in the hierarchy; Hispanics and other non-Asians are at the bottom.

The typical cost of a manicure in the city helps explain the abysmal pay. A survey of more than 105 Manhattan salons by The Times found an average price of about $10.50. The countrywide average is almost double that, according to a 2014 survey by Nails Magazine, an industry publication.

With fees so low, someone must inevitably pay the price.

“You can be assured, if you go to a place with rock-bottom prices, that chances are the workers’ wages are being stolen,” said Nicole Hallett, a lecturer at Yale Law School who has worked on wage theft cases in salons. “The costs are borne by the low-wage workers who are doing your nails.”

Until more people realize that a $10.50 manicure or a $6.00 tee shirt cannot be the means to earn a living wage for its producer (just do the math)….I doubt this exploitation will end.

In interviews, some owners readily acknowledged how little they paid their workers. Ms. Ren’s boss, Lian Sheng Sun, who goes by Howard, at first denied doing anything wrong, but then said it was just how business was done. “Salons have different ways of conducting their business,” he said. “We run our business our own way to keep our small business surviving.”

Many owners said they were helping new immigrants by giving them jobs.

“I want to change the first generation coming here and getting disgraced, and getting humiliated,” said Roger Liu, 28, an immigrant from China, seated inside the salon he owned, Relaxing Town Nails and Spa in Huntington Station, N.Y. As he spoke last summer, an employee, a woman in her 50s, paced the salon, studying a scrap of paper scribbled with the steps of a pedicure, chanting them to herself quietly in Chinese.

It was her first week working in a salon, she said. Mr. Liu was not paying her.

More to come Next week on This Story!